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United States of America

ST. HELENA, CALIFORNIA


Home > North America > United States > California
Elevation: 170 feet     Latitude: 38 26N     Longitude: 122 25W

WEATHER
 
CURRENT CONDITIONS

As of 20 May, 2019 @ 3:54 am EDT
(27 Minutes Ago)

Clear
Temperature
44.6°F
Humidity
93.4 %
Wind
4.6 mph
Sunrise/Set
08:53 am
11:18 pm
Visibility
10 mi
Dew Point
42.8 °F
Pressure
29.85 in hg
Local Time
4:20 am EDT
20 May, 2019
 
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MONTHLY - ALL WEATHER AVERAGES   [ Show Summary ]
[ °C ]   °F
TEMPERATURE 
Average Temperature
Years on Record: 30  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
F 59.247.450.854.257.163.267.669.369.567.762.253.647.5

Average High Temperature
Years on Record: 30  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
F 73.658.162.866.771.578.984.485.986.584.878.566.558.6

Average Low Temperature
Years on Record: 30  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
F 44.736.638.841.642.647.450.852.752.450.545.840.736.4

Highest Recorded Temperature
Years on Record: 30  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
F 8460.165.368.870.77681.676.6788476.669.761.5

Lowest Recorded Temperature
Years on Record: 30  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
F 39.739.742.543.644.449.152.854.353.554.451.444.939.9

Average Number of Days Above 100F/38C
Years on Record: 30  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
Days3.5---------------0.70.90.51.5---------

Average Number of Days Above 90F/32C
Years on Record: 76  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
Days 31.9------0.40.824.27.47.66.53.1------

Average Number of Days Above 80F/26C
Years on Record: 30  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
Days125.4------1.93.611.920.926.625.120.414.30.7---

Average Number of Days Above 70F/21C
Years on Record: 30  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
Days216.71.73.31018.127.629.73130.829.7259.50.3

Average Number of Days Above 60F/15C
Years on Record: 30  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
Days300.411.318.124.728.130.83031313030.524.210.7

Average Number of Days Above 50F/10C
Years on Record: 30  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
Days360.628.427.730.829.830.8303131303129.730.3

Average Number of Days Above 40F/4C
Years on Record: 30  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
Days365312831303130313130313031

Average Number of Days Below 70F/21C
Years on Record: 30  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
Days365312831303130313130313031

Average Number of Days Below 60F/15C
Years on Record: 30  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
Days362.93128313030.829.830.630.529.530.63031

Average Number of Days Below 50F/10C
Years on Record: 30  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
Days262.230.427.328.727.922.413.26.27.11426.42830.5

Average Number of Days Below 40F/4C
Years on Record: 30  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
Days99.220.917.313.19.50.8------------2.414.720.7

Average Number of Days Below 32F/0C
Years on Record: 76  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
Days 60.212.98.87.63.40.80.2------0.447.914.2



PRECIPITATION 
Average Precipitation
Years on Record: 30  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
in 33.86.36.84.81.91.20.2---0.10.31.546.8

Average Number of Days With Precipitation
Years on Record: 76  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
Days 601199531---11479

Most Reported Precipitation in a Month
Years on Record: 30  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
in 15.112.415.19.84.130.91.21.21.54.29.78.9

Least Reported Precipitation in a Month
Years on Record: 30  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
in ---0.30.2------------------------0.1---

Most Precipitation Reported in a Day
Years on Record: 76  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
in 6.55.84.642.70.81.11.20.32.7546.5

Avg. No. of Days w/Precip. Above 0.2in/5mm
Years on Record: 76  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
Days 45977311------1367

Avg. # of Days w/Precip. Above 0.4in/10mm
Years on Record: 76  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
Days 205431---------------133

Avg. No. of Days w/Precip. Above 1in/25mm
Years on Record: 76  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
Days 10321------------------112



PRECIPITATION - SNOW 
Average Snowfall
Years on Record: 76  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
in 0.10.1---------------------------------

Most Snow Reported in a Month
Years on Record: 76  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
in 33---------------------------------



DEGREE DAYS 
Heating Degree Days
Years on Record: 30  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
Days 268854739833924696216528117343542

Cooling Degree Days
Years on Record: 30  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
Days 567------383899139143107281---

Growing Degree Days
Years on Record: 30  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
Days3639215715121540852859860352937713022



SKY CONDITIONS 
Average Length of Day
Years on Record: 30  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
Hours12.710.311.312.513.714.815.31514.112.811.610.510



SOLAR RADIATION 
Average Daily Solar Radiation - Global
Years on Record: 22  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
kWh/m25.12.23.24.76.17.387.97.15.74.22.72

Average Daily Solar Radiation - Diffuse
Years on Record: 22  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
kWh/m21.30.81.11.31.71.81.81.71.51.210.80.7

Average Daily Solar Radiation - Reflected
Years on Record: 22  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
kWh/m25.63.54.45.76.36.66.96.96.96.65.84.23.4

Average Daily Solar Radiation - Direct
Years on Record: 22  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
kWh/m26.73.74.76.27.38.49.59.48.97.96.64.73.6

Maximum Daily Solar Radiation - Global
Years on Record: 22  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
kWh/m25.12.23.24.76.17.387.97.15.74.22.72

Maximum Daily Solar Radiation - Diffuse
Years on Record: 22  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
kWh/m21.50.91.21.61.92.42.221.71.41.20.90.8

Maximum Daily Solar Radiation - Reflected
Years on Record: 22  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
kWh/m26.54.66.17.377.37.37.57.57.26.45.35.1

Maximum Daily Solar Radiation - Direct
Years on Record: 22  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
kWh/m28.45.27.698.610.110.710.910.197.46.36.1

Minimum Daily Solar Radiation - Global
Years on Record: 22  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
kWh/m24.31.62.23.95.25.477.26.65.43.72.21.7

Minimum Daily Solar Radiation - Diffuse
Years on Record: 22  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
kWh/m210.70.70.91.41.51.51.31.210.90.70.5

Minimum Daily Solar Radiation - Reflected
Years on Record: 22  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
kWh/m24.62.22.74.55.34.96.16.36.56.153.22.6

Minimum Daily Solar Radiation - Direct
Years on Record: 22  Chart This
 ANNUAL  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC 
kWh/m251.92.34.25.34.67.47.97.975.33.22.5




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WEATHER FORECAST

As of 3:33 am 5/20/19 EDT

Monday
Light Clouds
63°
42°
Tuesday
Partly Cloudy
58°
45°
Wednesday
Partly Cloudy
71°
44°
Thursday
Light Clouds
70°
55°
Friday
Clear
69°
50°
Saturday
Cloudy
60°
49°
Sunday
Sun Showers
60°
48°

Forecast data from The Norwegian Meteorological Institute; Current conditions data from the National Weather Service
All historical data and normals © Weatherbase


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