Sunnyvale, CA Weather by Month and Climate Averages

How much rain does Sunnyvale get?

Sunnyvale gets 16.1 in of precipitation in an average year, spread over about 64 days with measurable rain. That is fewer rainy days than 72% of the US.

February is the wettest month, with 3.2 in. July is the driest, with 0.0 in. February has the most rainy days, about 11.

The longest dry spell in the last five years lasted 120 days, to September 9, 2025.

See where Sunnyvale ranks: rainiest cities in the US, US cities with the most rainy days, rainiest cities in California.

Sunnyvale weather by month

Sunnyvale weather in January

In January, Sunnyvale averages a high of 59°F and a low of 43°F. It gets 3.0 in of precipitation over about 10 rainy days. The sun is out about 39% of daylight hours. The January record high is 76°F (1988) and the record low is 27°F (1973).

Sunnyvale weather in February

In February, Sunnyvale averages a high of 62°F and a low of 46°F. It gets 3.2 in of precipitation over about 11 rainy days. The sun is out about 59% of daylight hours. The February record high is 81°F (1986) and the record low is 26°F (1989).

Sunnyvale weather in March

In March, Sunnyvale averages a high of 67°F and a low of 48°F. It gets 2.6 in of precipitation over about 9 rainy days. The sun is out about 45% of daylight hours. The March record high is 88°F (2026) and the record low is 31°F (1971). March is one of the most comfortable months to visit.

Sunnyvale weather in April

In April, Sunnyvale averages a high of 70°F and a low of 49°F. It gets 1.2 in of precipitation over about 6 rainy days. The sun is out about 57% of daylight hours. The April record high is 95°F (1989) and the record low is 36°F (1976). April is one of the most comfortable months to visit.

Sunnyvale weather in May

In May, Sunnyvale averages a high of 75°F and a low of 53°F. It gets 0.5 in of precipitation over about 4 rainy days. The sun is out about 65% of daylight hours. The May record high is 101°F (1984) and the record low is 39°F (1975). May is one of the most comfortable months to visit.

Sunnyvale weather in June

In June, Sunnyvale averages a high of 80°F and a low of 56°F. It gets 0.2 in of precipitation over about 1 rainy days. The sun is out about 71% of daylight hours. The June record high is 109°F (2000) and the record low is 43°F (1971). June is one of the most comfortable months to visit.

Sunnyvale weather in July

In July, Sunnyvale averages a high of 83°F and a low of 59°F. It gets 0.0 in of precipitation over about 0 rainy days. The sun is out about 79% of daylight hours. The July record high is 108°F (1972) and the record low is 48°F (1975).

Sunnyvale weather in August

In August, Sunnyvale averages a high of 83°F and a low of 59°F. It gets 0.0 in of precipitation over about 0 rainy days. The sun is out about 78% of daylight hours. The August record high is 105°F (1993) and the record low is 47°F (1973).

Sunnyvale weather in September

In September, Sunnyvale averages a high of 81°F and a low of 58°F. It gets 0.1 in of precipitation over about 1 rainy days. The sun is out about 75% of daylight hours. The September record high is 104°F (1971) and the record low is 45°F (1970).

Sunnyvale weather in October

In October, Sunnyvale averages a high of 75°F and a low of 53°F. It gets 0.8 in of precipitation over about 3 rainy days. The sun is out about 71% of daylight hours. The October record high is 106°F (2024) and the record low is 36°F (1971). October is one of the most comfortable months to visit.

Sunnyvale weather in November

In November, Sunnyvale averages a high of 65°F and a low of 47°F. It gets 1.4 in of precipitation over about 7 rainy days. The sun is out about 57% of daylight hours. The November record high is 83°F (1997) and the record low is 31°F (1993). November is one of the most comfortable months to visit.

Sunnyvale weather in December

In December, Sunnyvale averages a high of 59°F and a low of 43°F. It gets 3.1 in of precipitation over about 11 rainy days. The sun is out about 39% of daylight hours. The December record high is 74°F (2024) and the record low is 19°F (1990).

Sunshine, humidity and wind in Sunnyvale

July is the sunniest month in Sunnyvale, with sunshine about 79% of daylight hours. January is the cloudiest, at 39%. Over the year the sun shines about 61% of daylight hours. Sunnyvale is sunnier than 88% of the US.

Humidity peaks in December at 76% and is lowest in October at 57%.

Sunnyvale has about 19 days a year above 90°F. Sunnyvale is cooler than 62% of the US.

Thunderstorms occur on about 3 days a year.

See where Sunnyvale ranks: sunniest cities in the US, cloudiest cities in the US, hottest cities in the US.

First and last freeze in Sunnyvale

The first fall freeze in Sunnyvale typically comes around December 14, and the last spring freeze around January 18. That leaves a frost-free growing season of about 330 days.

Sunnyvale weather records

The hottest temperature on record at the Sunnyvale station is 109°F, on June 14, 2000. The coldest is 19°F, on December 22, 1990.

The wettest day on record brought 2.4 in of rain, on November 29, 1970.

30 all-time records have been set at the station since 1970.

The annual mean temperature has changed by +0.6°F per decade since 1970.

The best time to visit Sunnyvale

The most comfortable time to visit is typically March to June and October to November, when daytime highs sit near 72°F.

Winter (December–February) is mild, with average highs around 60°F and lows near 44°F.

Spring (March–May) is warm, with average highs around 71°F and lows near 50°F.

Summer (June–August) is warm, with average highs around 82°F and lows near 58°F.

Autumn (September–November) is warm, with average highs around 74°F and lows near 53°F.

Sunnyvale climate questions

How much rain does Sunnyvale get?

Sunnyvale gets 16.1 in of precipitation in an average year, over about 64 rainy days.

What is the wettest month in Sunnyvale?

February is the wettest month in Sunnyvale, with 3.2 in. July is the driest, with 0.0 in.

How many rainy days does Sunnyvale have a year?

Sunnyvale has about 64 days with measurable rain in an average year. February has the most, about 11.

What is the hottest month in Sunnyvale?

July is the warmest month in Sunnyvale, with an average high of 83°F.

What is the coldest month in Sunnyvale?

January is the coldest month in Sunnyvale, with an average low of 43°F.

What is the record high temperature in Sunnyvale?

The record high at the Sunnyvale station is 109°F, set on June 14, 2000. The record low is 19°F, on December 22, 1990.

What is the sunniest month in Sunnyvale?

July is the sunniest month in Sunnyvale, with sunshine about 79% of daylight hours. January is the cloudiest.

When is the first frost in Sunnyvale?

The first fall freeze in Sunnyvale typically comes around December 14. The last spring freeze is around January 18.

What is the best time to visit Sunnyvale?

The most comfortable time to visit is typically March to June and October to November, when daytime highs sit near 72°F.