April weather forecastSunnyvale, CA
April
Weather in April
In April, Sunnyvale experiences a Meteorological Spring with a noticeable rise in the average high temperatures, reaching 65.8°F (18.8°C). The rainfall significantly decreases to an average of 0.24" (6mm), making way for more extended clear sky periods. The relative humidity declines, and the total daylight hours increase to around 13.2, providing ample time for exploring the outdoors. With moderate visibility and an increase in the UV index, protection from the sun becomes essential during peak hours. The pleasant weather conditions in April make it one of the most appealing months of the year in Sunnyvale.Temperature
The commencement of April notes an average high-temperature of a still refreshing 65.8°F (18.8°C), exhibiting little difference from the previous month. Sunnyvale temperatures generally rest at a low of 46.6°F (8.1°C) during the April nights.Humidity
The average relative humidity in April is 70%.Rainfall
In Sunnyvale, during April, the rain falls for 6.1 days and regularly aggregates up to 0.24" (6mm) of precipitation. Throughout the year, there are 50 rainfall days, and 3.9" (99mm) of precipitation is accumulated.Daylight
In April, the average length of the day is 13h and 11min.On the first day of April, sunrise is at 6:52 am and sunset at 7:31 pm. On the last day of the month, sunrise is at 6:13 am and sunset at 7:57 pm PDT.
Sunshine
In Sunnyvale, the average sunshine in April is 10.5h.UV index
In April, the average daily maximum UV index is 5. A UV Index reading of 3 to 5 represents a medium health hazard from unprotected exposure to Sun's UV rays for the average person.Note: The average daily UV index of 5 in April transforms into the following instructions:
Put precautions into practice - Ensuring skin and eye safety is a necessity. The most potent solar radiation is around mid-day, so one should minimize exposure to direct sunlight during this period. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in April
Sunnyvale, CA
- Average high temperature in April: 65.8°F
The warmest month (with the highest average high temperature) is July (79.9°F).
The month with the lowest average high temperature is December (56.8°F).
- Average low temperature in April: 46.6°F
The month with the highest average low temperature is August (56.8°F).
The coldest months (with the lowest average low temperature) are February and December (44.2°F).
Average pressure in April
Sunnyvale, CA
- Average pressure in April: 30.04"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The months with the lowest atmospheric pressure are June and September (29.92"Hg).
Average wind speed in April
Sunnyvale, CA
- Average wind speed in April: 6.2mph
The windiest month (with the highest average wind speed) is April (6.2mph).
The calmest month (with the lowest average wind speed) is September (4.6mph).
Average humidity in April
Sunnyvale, CA
- Average humidity in April: 70%
The month with the highest relative humidity is March (73%).
The months with the lowest relative humidity are September and October (63%).
Average rainfall in April
Sunnyvale, CA
- Average rainfall in April: 0.24"
The wettest months (with the highest rainfall) are February and March (0.75").
The driest month (with the least rainfall) is July (0").
Average rainfall days in April
Sunnyvale, CA
- Average rainfall days in April: 6.1 days
The month with the highest number of rainy days is March (9.6 days).
The month with the least rainy days is August (0.4 days).
Average daylight in April /
Average sunshine in April
Sunnyvale, 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 30min
The month with the most sunshine is July (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 5h and 54min).
Average sunshine days in April
Sunnyvale, CA
- Average sunshine days in April: 23.1 days
The month with the most sunshine days is August (30.1 days).
The month with the least sunshine days is March (19.9 days).
Average UV index in April
Sunnyvale, CA
- Average UV index in April: 5
The month with the highest UV index is June (UV index 6).
The months with the lowest UV index are February, November and December (UV index 3).
Average cloud cover in April
Sunnyvale, CA
- Average cloud cover in April: 26
The month with the most cloud cover is March (Cloud cover 35).
The month with the least cloud cover is July (Cloud cover 7).
Average visibility in April
Sunnyvale, 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).
