Monthly Climatological Summary
Turlock, Stanislaus Co., CA (Lat 37^31'37"N, Lon 120^50'22"W, elev 123)
April 2000
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Temperature Degree Days Pcpn Bar Pressure Humidity PkWind
Max Min Heat Cool Max Min Max Min (MPH)
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01 84 43 1 0 .00 30.08 29.95 82 22 12
02 88 45 0 2 .00 30.04 29.94 96 24 10
03 91 52 0 7 .00 30.10 30.01 100 25 10
04 81 51 0 1 .00 30.16 30.03 100 36 14
05 80 46 2 0 .00 30.06 29.93 97 34 15
06 81 44 2 0 .00 30.13 30.03 93 27 14
07 82 44 2 0 .00 30.17 30.03 93 24 14
08 76 46 4 0 .00 30.11 30.02 100 30 20
09 75 45 5 0 .00 30.10 30.01 93 38 18
10 80 45 2 0 .00 30.05 29.97 100 36 17
11 85 53 0 4 .00 30.07 29.94 93 37 12
12 88 60 0 9 T 30.06 29.95 60 30 16
13 77 59 0 3 .06 30.09 29.93 87 34 18
14 74 54 1 0 .00 29.97 29.86 93 34 15
15 69 51 5 0 .00 29.96 29.86 89 44 14
16 65 54 5 0 .18 29.91 29.77 93 56 27
17 57 47 13 0 1.32 29.90 29.75 100 80 21
18 68 40 11 0 .00 30.13 29.90 100 39 9
19 72 43 7 0 .00 30.18 30.09 97 38 10
20 76 49 2 0 .00 30.13 29.97 89 40 14
21 79 51 0 0 .00 29.98 29.85 89 40 20
22 70 48 6 0 .00 30.13 29.98 93 47 14
23 71 42 8 0 .00 30.20 30.11 100 38 20
24 78 45 3 0 .00 30.16 30.03 100 32 16
25 80 50 0 0 .00 30.16 30.06 87 41 17
26 85 51 0 3 .00 30.10 29.94 96 37 14
27 80 53 0 2 .00 30.09 29.91 74 31 31
28 68 48 7 0 .00 30.16 30.07 69 28 23
29 78 43 4 0 .00 30.18 30.09 89 26 17
30 86 48 0 2 .00 30.15 30.03 93 28 12
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Means and Totals for April 2000
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Average Maximum Temperature: 77.4
Average Minimum Temperature: 48.3
Mean Temperature: 62.9 (+ 1.2)
Maximum Temperature: 91 (4-03-00)
Minimum Temperature: 40 (4-18-00)
Degree Days Heating: 90
Degree Days Cooling: 33
Days with temperature 90F+: 1
Days with temperature <32F: 0
Precipitation: 1.56 (+ .70) Season: 12.31
Greatest one-day rainfall: 1.32 (4-17-00)
Snowfall: 0.0 (Avg) Season: 0.0
Maximum Pressure: 30.20 (4-23-00)
Minimum Pressure: 29.75 (4-17-00)
Minimum RH: 22% (4-01-00)
Days with measurable pcpn: 3
Days with pcpn 1.00"+: 1
Thunderstorm days: 0
Fog days: 0
Peak Wind Gust (MPH): 31 (4-27-00)
NOTICE: All temperatures are in degrees Fahrenheit, precipitation
values in inches, pressure in inches Hg, and wind speeds
in MPH.
Summary....April 2000 in the northern San Joaquin Valley was reminiscent of Aprils in the late 1980s and early 1990s - warmest at the beginning of the month, wettest at mid-month, and coolest towards the end of the month. The temperature topped 90F for the first time this year on the 3rd, the earliest in the year the temp had reached 90F here since 1988. All of the month's rain came during a five day span in the middle of the month. The .06 inch of rain that fell here on the 13th broke a 34-day streak without measureable precipitation. Thunderstorms developed 25-35 miles north of here that afternoon, and as the storms grazed the far northeastern tip of the county, a severe thunderstorm warning was issued for that area. A break between storms came on the 14th-15th, although the weather wasn't totally calm across the area those two days. The Apr 15 issue of the Modesto Bee reported that a "twister" tore the roof off a carport at a mobile home park in east Modesto on the 14th (ed. note: It was probably a dust devil). What has proven to be this station's heaviest rainfall event of the 1999-2000 rainy season began late on the 16th and continued for much of the 17th. The 1.32 inch rainfall total on the 17th was the first one-day rainfall total over 1 inch recorded at this station since records began in 1987. The previous one-day rainfall record for April was .78 inch on Apr 23, 1988. Cool onshore breezes generally kept temperatures under 80F for the rest of the month. These pushes of marine air were for the most part nondescript, although the one on the 27th gave us wind gusts to 31 mph and brought the coastal stratus all the way into the valley.
I will be on vacation from May 5-15. Matt Wear will take over the daily temperature and precipitation readings for those days, so those data will be complete for the May summary.
Following are monthly data from ASOS/AWOS stations in the San Joaquin Valley.....
STATION AVERAGE TEMP |EXTREME TEMP | PRECIPITATION
Max Min Mean Dep|Max Dy Min Dy|Total Dep Max Dy
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Stockton 75.5|46.2|60.8|+1.5| 88| 3| 38| 7| 1.20|+ .12|1.03|17|(a)
Modesto 75.2|49.1|62.1|+1.9| 88| 3| 43|18| 2.00|+1.03|1.69|17|(a)
Merced 74.8|45.8|60.3|+0.7| 87| 3| 38| 7| 2.06|+1.00|1.97|17|(a)
Madera 77.3|47.1|62.2|+2.3| 89| 3| 40| 1| 1.02|- .15| .93|17|
Fresno 77.4|50.9|64.1|+2.9| 91| 3| 44|18| 1.16|+ .19| .97|17|(a)
Hanford 77.7|50.6|64.2|+4.2| 90|12| 45|29| .97|+ .23| .88|17|
Visalia 76.4|48.9|62.7|+1.6| 90|12| 43|29| 1.04|+ .05|1.01|17|(b)
Porterville 76.6|46.3|61.5|-0.3| 88|27| 39|29| .89|- .20| .65|17|(b)
Bakersfield 76.7|49.0|62.9|-0.1| 90|12| 39|19| .57| .00| .52|17|
(a) Maximum one-day rainfall total was for period beginning midnight
PDT on the 17th.
(b) Maximum and minimum temperatures are rounded to the nearest
whole degree Celsius, then converted to Fahrenheit.