2001 Sacramento, California (SAC)

views updated

2001 SACRAMENTO, CALIFORNIA (SAC)

Sacramento, and the lower Sacramento Valley, has a mild climate with abundant sunshine most of the year. A nearly cloud–free sky prevails throughout the summer months, and in much of the spring and fall. The summers are usually dry with warm to hot afternoons and mostly mild nights. The rainy season generally is November through March. About 75 percent of the annual precipitation occurs then, but measurable rain falls only on an average of nine days per month during that period. The shielding effect of mountains to the north, east, and west usually modifies winter storms. The Sierra Nevada snow fields, only 70 miles east of Sacramento, usually provide an adequate water supply during the dry season, and an important recreational area in winter. Heavy snowfall and torrential rains frequently fall on the western Sierra slopes, and may produce flood conditions along the Sacramento River and its tributaries. In the valley, however, excessive rainfall as well as damaging winds are rare.

The prevailing wind at Sacramento is southerly every month but November, when it is northerly. Topographic effects, the north–south alignment of the valley, the coast range, and the Sierra Nevada strongly influence the wind flow in the valley. A sea level gap in the coast range permits cool, oceanic air to flow, occasionally, into the valley during the summer season with a marked lowering of temperature through the Sacramento–San Joaquin River Delta to the capital. In the spring and fall, a large north–to–south pressure gradient develops over the northern part of the state. Air flowing over the Siskiyou mountains to the north warms and dries as it descends to the valley floor. This gusty, blustery north wind is a local variation of the chinook. It apparently carries a form of pollen which may cause allergic responses by susceptible individuals.

As is well known, relative humidity has a marked influence on the reactions of plants and animals to temperature. The extremely low relative humidity that ordinarily accompanies high temperatures in this valley should be considered when comparing temperatures here with those of cities in more humid regions. The extreme hot spells, with temperatures exceeding 100 degrees, are usually caused by air flow from a sub–tropical high pressure area that brings light to nearly calm winds and humidities below 20 percent.

Thunderstorms are few in number, usually mild in character, and occur mainly in the spring. An occasional thunderstorm may drift over the valley from the Sierra Nevada in the summer. Snow falls so rarely, and in such small amounts, that its occurrence may be disregarded as a climatic feature. Heavy fog occurs mostly in midwinter, never in summer, and seldom in spring or autumn. An occasional winter fog, under stagnant atmospheric conditions, may continue for several days. Light and moderate fogs are more frequent, and may come anytime during the wet, cold season. The fog is the radiational cooling type, and is usually confined to the early morning hours.

Sacramento is the geographical center of the great interior valley of California that reaches from Red Bluff in the north to Bakersville in the south. This predominantly agricultural region produces an extremely wide and abundant variety of fruits, grains, and vegetables ranging from the semi–tropical to the hardier varieties.

Based on the 1951–1980 period, the average first occurrence of 32 degrees Fahrenheit in the fall is December 1 and the average last occurrence in the spring is February 14.

NORMALS, MEANS, AND EXTREMES

SACRAMENTO, CA (SAC)

LATITUDE:    LONGITUDE:    ELEVATION (FT):    TIME ZONE:    WBAN: 23232

38 30′ 45″ N  121 29′ 33″ W  GRND: 38 BARO: 41  PACIFIC (UTC + 8)

ELEMENTPORJANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDECYEAR
TEMPERATURE FNORMAL DAILY MAXIMUM3052.760.064.071.180.387.893.292.187.377.963.152.773.5
MEAN DAILY MAXIMUM5453.159.764.371.480.087.290.991.587.677.863.653.473.4
HIGHEST DAILY MAXIMUM51707688951051151141101081048772115
YEAR OF OCCURRENCE199119921988199619841961197219961988200119601999JUN 1961
MEAN OF EXTREME MAXS.5463.369.776.285.595.5102.8102.8103.4100.292.076.364.086.0
NORMAL DAILY MINIMUM3037.741.443.245.550.355.358.158.055.750.443.437.848.1
MEAN DAILY MINIMUM5438.241.443.045.850.555.156.757.755.950.242.837.947.9
LOWEST DAILY MINIMUM5123232631364148494336261818
YEAR OF OCCURRENCE197919891971199919741990198319781978198919931990DEC 1990
MEAN OF EXTREME MINS.5427.731.534.137.742.148.051.352.048.741.532.328.239.6
NORMAL DRY BULB3045.250.753.658.365.371.675.775.171.564.253.345.360.8
MEAN DRY BULB5445.850.553.858.765.171.174.074.671.764.053.245.660.7
MEAN WET BULB1643.847.150.052.355.759.758.556.155.551.545.039.851.2
MEAN DEW POINT1640.943.145.245.948.351.751.449.348.544.740.836.845.5
NORMAL NO. DAYS WITH:
MAXIMUM 90300.00.00.00.45.812.522.520.012.42.80.00.076.4
MAXIMUM 3230*0.00.00.00.00.00.00.00.00.00.0*0.0
MINIMUM 32307.01.80.50.00.00.00.00.00.00.01.26.917.4
MINIMUM 0300.00.00.00.00.00.00.00.00.00.00.00.00.0
H/CNORMAL HEATING DEG. DAYS3061440035723080120016783516112749
NORMAL COOLING DEG. DAYS30000298921033231321153001237
RHNORMAL (PERCENT)3083777264595553565763768366
HOUR 04 LST3090878482817876787780869082
HOUR 10 LST3085776958504747505057748462
HOUR 16 LST3070595343353128293138587045
HOUR 22 LST3086817773696461646570818673
SPERCENT POSSIBLE SUNSHINE4748657482909497969386664978
W/OMEAN NO. DAYS WITH:
HEAVY FOG (VISBY 1/4 MI)5310.05.21.70.30.20.00.00.00.21.45.29.433.6
THUNDERSTORMS530.40.60.80.70.40.30.20.10.50.30.20.24.7
CLOUDINESSMEAN:
SUNRISE–SUNSET (OKTAS)485.75.04.53.82.91.80.91.11.52.64.55.53.3
MIDNIGHT–MIDNIGHT (OKTAS)315.34.63.93.32.31.70.81.01.22.13.94.82.9
MEAN NO. DAYS WITH:
CLEAR496.57.69.911.916.921.726.925.123.218.99.87.6186.0
PARTLY CLOUDY495.97.08.79.68.65.93.24.14.26.07.45.876.4
CLOUDY4918.713.612.48.45.52.41.01.32.15.412.417.0100.2
PRMEAN STATION PRESSURE(IN)2430.1030.0529.9929.9829.9029.8629.8529.8629.8629.9630.0630.1229.97
MEAN SEA–LEVEL PRES. (IN)1630.1330.0730.0330.0029.9329.8729.8729.8729.8829.9730.0930.1529.99
WINDSMEAN SPEED (MPH)367.17.88.58.69.09.59.18.77.36.66.16.47.9
PREVAIL. DIR (TENS OF DEGS)2114142222222120202120141421
MAXIMUM 2–MINUTE:
SPEED (MPH)335333633382926222536383138
DIR. (TENS OF DEGS)14243235333323222135151515
YEAR OF OCCURRENCE200120002000199920012000199920012000200020012001NOV 2001
MAXIMUM 5–SECOND:
SPEED (MPH)348404443463531293244494449
DIR. (TENS OF DEGS)13231435333322212234161416
YEAR OF OCCURRENCE200120002001199920012000200120002000200020012001NOV 2001
PRECIPITATIONNORMAL (IN)303.732.872.571.160.270.120.050.070.371.082.722.5117.52
MAXIMUM MONTHLY (IN)629.699.958.134.763.131.260.790.652.787.517.4112.6412.64
YEAR OF OCCURRENCE199519981995194119481993197419761989196219701955DEC 1955
MINIMUM MONTHLY (IN)620.160.150.050.00T0.000.000.000.000.00T0.000.00
YEAR OF OCCURRENCE198419641994194919921981198319821980196619951989DEC 1989
MAXIMUM IN 24 HOURS (IN)533.413.012.302.221.381.21T0.320.505.592.953.645.59
YEAR OF OCCURRENCE196719861982195819941993200119972001196219701955OCT 1962
NORMAL NO. DAYS WITH:
PRECIPITATION 0.01309.68.18.65.12.11.10.30.51.73.67.98.757.3
PRECIPITATION 1.00300.80.50.30.1*0.00.00.0*0.20.60.32.8
SNOWFALLNORMAL (IN)30T0.10.00.00.00.00.00.00.00.00.0T0.1
MAXIMUM MONTHLY (IN)50T2.0T0.0T0.00.00.00.00.00.0T2.0
YEAR OF OCCURRENCE19741976198219941995FEB 1976
MAXIMUM IN 24 HOURS (IN)50T2.0T0.0T0.00.00.00.00.00.0T2.0
YEAR OF OCCURRENCE19741976198219941995FEB 1976
MAXIMUM SNOW DEPTH (IN)480000000000000
YEAR OF OCCURRENCE
NORMAL NO. DAYS WITH:
SNOWFALL 1.0300.00.*0.00.00.00.00.00.00.00.00.00.00.0
PRECIPITATION (inches) 2001 SACRAMENTO, CA (SAC)
YEARJANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDECANNUAL
19720.811.280.291.390.280.190.000.000.901.755.141.8813.91
19736.875.642.760.050.130.000.000.000.331.646.272.7926.48
19743.581.373.270.960.010.500.79T0.001.160.662.8615.16
19750.734.594.280.81TT0.040.23T2.030.290.1813.18
19760.361.490.441.530.000.040.000.650.520.020.550.656.25
19771.171.171.270.300.730.00T0.000.760.121.924.2711.71
19789.144.463.382.31TT0.00T0.30T3.200.9523.74
19795.664.552.470.760.140.000.250.00T1.621.483.4120.34
19805.647.122.621.060.490.040.400.000.000.060.121.7919.34
19814.560.873.550.660.500.000.000.000.252.576.093.2822.33
19825.502.357.123.07T0.150.000.001.812.615.743.2531.60
19834.925.566.754.210.250.400.000.110.660.404.915.2633.43
19840.161.221.350.340.010.10T0.010.071.393.611.239.49
19850.661.522.01T0.010.15T0.060.560.533.722.3411.56
19863.678.603.200.910.070.000.000.000.600.190.140.7618.14
19872.293.233.050.20TT0.000.000.001.282.533.2515.83
19882.960.990.171.580.890.190.000.000.000.191.682.7311.38
19890.711.256.290.310.060.430.000.202.781.761.320.0015.11
19904.972.910.930.732.100.00T0.000.000.090.431.6013.76
19910.363.106.140.290.250.53T0.140.041.250.191.6013.89
19921.395.472.050.92T0.150.00T0.001.310.284.9416.51
19938.634.942.390.631.141.260.000.000.000.472.281.7523.49
19942.123.150.050.671.680.000.000.002.68
19959.690.208.131.461.060.470.000.000.00TT5.4926.50
19964.165.491.731.250.790.000.00TT0.671.976.3922.45
19979.050.280.340.180.350.590.000.320.160.824.562.9119.56
19986.409.952.471.052.980.580.000.000.230.762.840.5827.84
19992.634.451.500.890.070.030.00T0.000.181.630.0611.44
20006.498.492.031.391.170.040.00T0.091.620.680.5922.59
20013.754.572.041.50T0.08T0.000.500.362.436.2721.50
POR=62 YRS3.833.132.521.780.500.150.030.070.360.902.282.9918.54
AVERAGE TEMPERATURE (F) 2001 SACRAMENTO, CA (SAC)
YEARJANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDECANNUAL
197241.051.458.658.666.972.576.075.969.562.049.740.660.2
197344.353.151.160.869.474.676.874.270.863.451.946.961.4
197446.348.454.156.663.870.574.174.072.266.353.246.460.5
197543.449.250.351.868.273.277.376.977.465.154.647.461.2
197647.251.954.657.970.173.976.573.471.866.156.746.562.2
197743.852.451.062.259.472.274.273.968.863.954.549.660.5
197850.351.957.255.866.470.075.175.069.665.949.841.760.7
197945.348.854.656.966.771.975.673.174.664.051.746.760.8
198046.951.951.659.662.766.875.071.469.463.753.545.459.8
198146.850.451.257.964.774.875.174.569.763.560.348.661.5
198242.050.550.855.564.666.272.171.768.261.046.943.057.7
198343.152.253.454.764.270.872.276.674.967.553.751.061.2
198448.250.258.158.770.071.778.375.375.562.853.645.162.3
198542.451.450.861.563.275.177.072.968.563.349.842.659.9
198651.454.758.858.465.571.675.075.266.264.855.545.761.9
198744.951.353.862.769.172.471.874.971.867.653.447.261.7
198848.054.258.060.964.772.980.475.972.566.553.846.262.8
198944.147.155.663.265.871.776.273.869.662.454.344.360.7
199047.548.655.463.465.572.477.776.674.066.653.041.061.8
199147.355.051.058.063.370.277.173.274.868.855.946.361.7
199243.654.156.262.170.670.975.377.072.466.653.444.162.2
199345.249.557.958.464.671.774.374.171.565.051.544.360.7
199447.048.856.760.165.371.674.075.271.747.643.7
199551.352.153.057.763.169.074.275.172.359.351.1
199648.254.356.761.167.073.378.778.371.063.955.051.163.2
199748.352.757.962.471.972.976.575.975.164.156.946.263.4
199849.750.455.157.558.767.074.876.872.661.352.542.559.9
199944.748.150.857.462.869.972.073.072.365.154.646.859.8
200048.851.455.560.765.773.272.174.071.261.948.647.060.8
200145.848.857.255.971.773.473.474.571.165.855.948.861.9
POR=61 YRS45.750.453.858.665.070.974.174.471.663.953.145.860.6

REFERENCE NOTES:

PAGE 1:

THE TEMPERATURE GRAPH SHOWS NORMAL MAXIMUM AND NORMAL MINIMUM DAILY TEMPERATURES (SOLID CURVES) AND THE ACTUAL DAILY HIGH AND LOW TEMPERATURES (VERTICAL BARS).

PAGE 2 AND 3:

H/C INDICATES HEATING AND COOLING DEGREE DAYS.

RH INDICATES RELATIVE HUMIDITY

W/O INDICATES WEATHER AND OBSTRUCTIONS

S INDICATES SUNSHINE.

PR INDICATES PRESSURE.

CLOUDINESS ON PAGE 3 IS THE SUM OF THE CEILOMETER AND SATELLITE DATA NOT TO EXCEED EIGHT EIGHTHS (OKTAS).

GENERAL:

T INDICATES TRACE PRECIPITATION, AN AMOUNT GREATER THAN ZERO BUT LESS THAN THE LOWEST REPORTABLE VALUE.

+ INDICATES THE VALUE ALSO OCCURS ON EARLIER DATES.

BLANK ENTRIES DENOTE MISSING OR UNREPORTED DATA.

NORMALS ARE 30–YEAR AVERAGES (1961–1990).

ASOS INDICATES AUTOMATED SURFACE OBSERVING SYSTEM.

PM INDICATES THE LAST DAY OF THE PREVIOUS MONTH.

POR (PERIOD OF RECORD) BEGINS WITH THE JANUARY DATA MONTH AND IS THE NUMBER OF YEARS USED TO COMPUTE THE MEAN. INDIVIDUAL MONTHS WITHIN THE POR MAY BE MISSING.

WHEN THE POR FOR A NORMAL IS LESS THAN 30 YEARS, THE NORMAL IS PROVISIONAL AND IS BASED ON THE NUMBER OF YEARS INDICATED.

0.* OR * INDICATES THE VALUE OR MEAN–DAYS–WITH IS BETWEEN 0.00 AND 0.05.

CLOUDINESS FOR ASOS STATIONS DIFFERS FROM THE NON–ASOS OBSERVATION TAKEN BY A HUMAN OBSERVER. ASOS STATION CLOUDINESS IS BASED ON TIME–AVERAGED CEILOMETER DATA FOR CLOUDS AT OR BELOW 12,000 FEET AND ON SATELLITE DATA FOR CLOUDS ABOVE 12,000 FEET.

THE NUMBER OF DAYS WITH CLEAR, PARTLY CLOUDY, AND CLOUDY CONDITIONS FOR ASOS STATIONS IS THE SUM OF THE CEILOMETER AND SATELLITE DATA FOR THE SUNRISE TO SUNSET PERIOD.

GENERAL CONTINUED:

CLEAR INDICATES 0–2 OKTAS, PARTLY CLOUDY INDICATES 3–6 OKTAS, AND CLOUDY INDICATES 7 OR 8 OKTAS. WHEN AT LEAST ONE OF THE ELEMENTS (CEILOMETER OR SATELLITE) IS MISSING, THE DAILY CLOUDINESS IS NOT COMPUTED.

WIND DIRECTION IS RECORDED IN TENS OF DEGREES (2 DIGITS) CLOCKWISE FROM TRUE NORTH. "00" INDICATES CALM. "36" INDICATES TRUE NORTH.

RESULTANT WIND IS THE VECTOR AVERAGE OF THE SPEED AND DIRECTION.

AVERAGE TEMPERATURE IS THE SUM OF THE MEAN DAILY MAXIMUM AND MINIMUM TEMPERATURE DIVIDED BY 2.

SNOWFALL DATA COMPRISE ALL FORMS OF FROZEN PRECIPITATION, INCLUDING HAIL.

A HEATING (COOLING) DEGREE DAY IS THE DIFFERENCE BETWEEN THE AVERAGE DAILY TEMPERATURE AND 65 F.

DRY BULB IS THE TEMPERATURE OF THE AMBIENT AIR.

DEW POINT IS THE TEMPERATURE TO WHICH THE AIR MUST BE COOLED TO ACHIEVE 100 PERCENT RELATIVE HUMIDITY.

WET BULB IS THE TEMPERATURE THE AIR WOULD HAVE IF THE MOISTURE CONTENT WAS INCREASED TO 100 PERCENT RELATIVE HUMIDITY.

ON JULY 1, 1996, THE NATIONAL WEATHER SERVICE BEGAN USING THE "METAR" OBSERVATION CODE THAT WAS ALREADY EMPLOYED BY MOST OTHER NATIONS OF THE WORLD. THE MOST NOTICEABLE DIFFERENCE IN THIS ANNUAL PUBLICATION WILL BE THE CHANGE IN UNITS FROM TENTHS TO EIGHTS (OKTAS) FOR REPORTING THE AMOUNT OF SKY COVER.

HEATING DEGREE DAYS (base 65 F) 2001 SACRAMENTO, CA (SAC)
YEARJULAUGSEPOCTNOVDECJANFEBMARAPRMAYJUNTOTAL
1972–730061154517496363254241411512863
1973–74000773845535714563322519392726
1974–75700443475696614354493896912971
1975–7600072306539547374315211132368
1976–77001442525676503454249218792571
1977–780017683094724513622352694602229
1978–790011514497156064463132365722886
1979–80000100391558551373408164107292681
1980–812041343395965574054202298122769
1981–820096614549870839843428270402650
1982–8330311255326756703533543039943149
1983–84300733342551442120619122112133
1984–8500011533561169337743312289112786
1985–860215954506894112841922007302411
1986–87005347277593614377340953702433
1987–881001133954452230721213894272195
1988–89003383295766404962851065032526
1989–900011107316634536453289715362476
1990–910002435673954327442720510462678
1991–9200082267572657310265104092266
1992–930002434064360542621420255212530
1993–94005333996345504492481474812514
1994–9500051565441535436421010526
1995–96000166421513302250154211
1996–97000121294423511336214104712011
1997–9800056248577465404299233190132485
1998–9900811336768962146543123992293054
1999–00100573035564963892911388322316
2000–01045123484551588445240276402720
2001–00044264496
COOLING DEGREE DAYS (base 65 F) 2001 SACRAMENTO, CA (SAC)
YEARJANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDECANNUAL
1972006512924535134914730001262
19730001915629537329318134001351
197400056118029628522289001138
1975000017725838837537581001654
1976001816727836327021383801391
1977000121923029028413940001014
197800009815731831515787001132
1979000011721433626029572001294
1980000842913172071459900909
1981000267830331830115528701216
198200026783230213133900737
198300008118323536830492001263
1984000618321641932732057001528
1985000224131938025412848001192
198600109952073153219547001099
198700034171234220314212100001285
1988005228826948434623392001539
1989001608321135428015832001179
1990000337523639936727682001468
1991000354171379261300208001376
19920002318019333038123181001419
199300194922729429120738001116
199400096720528532020900
199500005415229432222800
1996000429125843042218796001526
199700131227244362348312331101569
1998000122783113712418001023
1999000173018422525322569001003
20000021511125522729019832001130
2001004921925926630019075001322
SNOWFALL (inches) 2001 SACRAMENTO, CA (SAC)
YEARJULAUGSEPOCTNOVDECJANFEBMARAPRMAYJUNTOTAL
1972–730.00.00.00.00.0T0.00.00.00.00.00.0T
1973–740.00.00.00.00.00.0T0.00.00.00.00.0T
1974–750.00.00.00.00.00.00.00.00.00.00.00.00.0
1975–760.00.00.00.00.00.00.02.00.00.00.00.02.0
1976–770.00.00.00.00.00.00.00.00.00.00.00.00.0
1977–780.00.00.00.00.00.00.00.00.00.00.00.00.0
1978–790.00.00.00.00.00.00.00.00.00.00.00.00.0
1979–800.00.00.00.00.00.00.00.00.00.00.00.00.0
1980–810.00.00.00.00.00.00.00.00.00.00.00.00.0
1981–820.00.00.00.00.00.00.00.0T0.00.00.0T
1982–830.00.00.00.00.00.00.00.00.00.00.00.00.0
1983–840.00.00.00.00.00.00.00.00.00.00.00.00.0
1984–850.00.00.00.00.00.00.00.00.00.00.00.00.0
1985–860.00.00.00.00.00.00.00.00.00.00.00.00.0
1986–870.00.00.00.00.00.00.00.00.00.00.00.00.0
1987–880.00.00.00.00.00.00.00.00.00.00.00.00.0
1988–890.00.00.00.00.0T0.00.00.00.00.00.0T
1989–900.00.00.00.00.00.00.00.00.00.00.00.00.0
1990–910.00.00.00.00.00.00.00.00.00.00.00.00.0
1991–920.00.00.00.00.00.00.00.00.00.00.00.00.0
1992–930.00.00.00.00.0T0.00.00.00.00.00.0T
1993–940.00.00.00.00.0T0.0T0.00.0T0.0T
1994–950.00.00.00.00.00.00.00.00.00.0
1995–960.00.00.00.00.0T0.0T0.00.00.00.0T
1996–970.00.00.00.00.00.00.00.00.00.00.00.00.0
1997–980.00.00.00.00.00.00.00.00.0
1998–99
1999–00
2000–01
2001–
POR=48 YRS0.00.00.00.00.0TT0.0T0.0T0.0T

More From encyclopedia.com

About this article

2001 Sacramento, California (SAC)

Updated About encyclopedia.com content Print Article

You Might Also Like

    NEARBY TERMS

    2001 Sacramento, California (SAC)