April weather forecastPortola Valley, CA
April
Weather in April
April in Portola Valley, California, is a refreshing spring month, with temperature in the range of an average high of 62.2°F (16.8°C) and an average low of 48.2°F (9°C).Temperature
In April, Portola Valley's weather conditions record an average high-temperature of a comfortable 62.2°F (16.8°C), demonstrating little divergence from the preceding month. Throughout April in Portola Valley, a steady low-temperature average of 48.2°F (9°C) is noted.Humidity
In April, the average relative humidity is 74%.Rainfall
In Portola Valley, in April, it is raining for 5.8 days, with typically 0.24" (6mm) of accumulated precipitation. In Portola Valley, during the entire year, the rain falls for 57.5 days and collects up to 4.76" (121mm) of precipitation.Daylight
The average length of the day in April is 13h and 11min.On the first day of April in Portola Valley, sunrise is at 6:52 am and sunset at 7:32 pm. On the last day of the month, sunrise is at 6:13 am and sunset at 7:58 pm PDT.
Sunshine
In Portola Valley, the average sunshine in April is 10.4h.UV index
In April, the average daily maximum UV index in Portola Valley, California, is 4. A UV Index reading of 3 to 5 represents a medium vulnerability from unsafe exposure to UV radiation for the ordinary person.Note: An average UV index of 4 in April transforms into this advice:
Take precautions - Protection against sun damage is advised. The Sun's UV radiation is especially harmful around midday, so reduce exposure and stay safe. Sunglasses that guard against UVA and UVB rays are pivotal in minimizing sun-induced ocular damage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in April
Portola Valley, CA
- Average high temperature in April: 62.2°F
The warmest month (with the highest average high temperature) is August (73°F).
The month with the lowest average high temperature is December (55.8°F).
- Average low temperature in April: 48.2°F
The months with the highest average low temperature are August and September (56.7°F).
The coldest months (with the lowest average low temperature) are January and February (46.4°F).
Average pressure in April
Portola Valley, CA
- Average pressure in April: 30.04"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is September (29.92"Hg).
Average wind speed in April
Portola Valley, CA
- Average wind speed in April: 7.6mph
The windiest month (with the highest average wind speed) is April (7.6mph).
The calmest month (with the lowest average wind speed) is August (5.5mph).
Average humidity in April
Portola Valley, CA
- Average humidity in April: 74%
The month with the highest relative humidity is March (76%).
The month with the lowest relative humidity is October (68%).
Average rainfall in April
Portola Valley, CA
- Average rainfall in April: 0.24"
The wettest month (with the highest rainfall) is February (0.98").
The driest month (with the least rainfall) is June (0.04").
Average rainfall days in April
Portola Valley, CA
- Average rainfall days in April: 5.8 days
The month with the highest number of rainy days is March (10.6 days).
The month with the least rainy days is June (0.9 days).
Average daylight in April /
Average sunshine in April
Portola Valley, CA
- Average daylight in April: 13h and 12min
The month with the longest days is June (Average daylight: 14h and 42min).
The month with the shortest days is December (Average daylight: 9h and 36min).
- Average sunshine in April: 10h and 24min
The month with the most sunshine is July (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 5h and 54min).
Average sunshine days in April
Portola Valley, CA
- Average sunshine days in April: 22.2 days
The months with the most sunshine days are June and July (26.3 days).
The month with the least sunshine days is March (18.3 days).
Average UV index in April
Portola Valley, CA
- Average UV index in April: 4
The months with the highest UV index are June, July, August and September (UV index 5).
The months with the lowest UV index are February, November and December (UV index 3).
Average cloud cover in April
Portola Valley, CA
- Average cloud cover in April: 27
The month with the most cloud cover is March (Cloud cover 35).
The month with the least cloud cover is July (Cloud cover 9).
Average visibility in April
Portola Valley, CA
- Average visibility in April: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).





