Cupertino, United States Weather & Climate 2026

Csb Warm-Summer Mediterranean

Monthly climate averages for Cupertino, United States. Based on 10-year ERA5 reanalysis data.

Climate Overview

Cupertino, United States experiences average highs of 22°C (72°F) and lows of 11°C (52°F) throughout the year. The climate is relatively dry, with only 5 rainy days per month on average. Sunshine is abundant, averaging about 10 hours per day. Average highs have stayed broadly stable across the available records.

Drier season: May–Oct Wetter season: Jan–Dec

At-a-Glance Climate Summary

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Key figures

Climate Score
8.1/10
Best: June, July, August, September, October
UV Index
6
High
Temperature 22°C / 11°C
Feels Like 21°C / 10°C
Rainy Days 5
Rainfall 56 mm
Sunshine 10 h
Humidity 71%
Wind Speed 12 km/h
Dew Point 11°C
Best Time to Visit
Hottest Month
28°C
August
Avg Low16°C
Rain0days
Coldest Month
7°C
January
Avg High15°C
Rain10days
Driest Month
0days
June
Avg High26°C
Avg Low13°C
Windiest Month
14 km/h
February (Gusts 42)
Sea Temperature
12°C16°C
Warmest water: September ( 15.9°C )

Worst Time to Visit

Consider avoiding January, February, December due to less favorable weather conditions.

Sun Position
Sunrise 05:48
Daylight 14.7h
Sunset 20:32

14-Day Forecast

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Live conditions

Cupertino on the map · live conditions

Cupertino, United States

Continent
Americas
City
Cupertino
Population
60.6K
Elevation
72 m
Coordinates
37.32°, -122.03°

Seasonal Breakdown

Spring
Mar–May
Avg High 20°C
Avg Low 10°C
Rain 6 days/mo
Summer
Jun–Aug
Avg High 27°C
Avg Low 14°C
Rain 0 days/mo
3/3 best months
Autumn
Sep–Nov
Avg High 24°C
Avg Low 13°C
Rain 3 days/mo
2/3 best months
Winter
Dec–Feb
Avg High 16°C
Avg Low 7°C
Rain 9 days/mo

Climate Charts

Based on historical averages (2016–2025)

Monthly Temperatures

36°C 30°C 24°C 18°C 12°C 6°C 0°C -6°C JanFebMarAprMayJunJulAugSepOctNovDec
HighLowShaded bands show the typical range across the available yearly records.

Line chart showing monthly temperatures. Jan: 15°C / 7°C . Feb: 16°C / 7°C . Mar: 17°C / 8°C . Apr: 20°C / 10°C . May: 22°C / 11°C . Jun: 26°C / 13°C . Jul: 28°C / 15°C . Aug: 28°C / 16°C . Sep: 28°C / 16°C . Oct: 25°C / 14°C . Nov: 19°C / 10°C . Dec: 16°C / 7°C .

Monthly Rainfall

0 mm 26 mm 52 mm 78 mm 104 mm 130 mm JanFebMarAprMayJunJulAugSepOctNovDec
Rainfall

Bar chart showing monthly rainfall. Jan: 150 mm. Feb: 122 mm. Mar: 127 mm. Apr: 34 mm. May: 18 mm. Jun: 0 mm. Jul: 0 mm. Aug: 1 mm. Sep: 5 mm. Oct: 31 mm. Nov: 66 mm. Dec: 121 mm.

Monthly Humidity

0% 25% 50% 75% 100% JanFebMarAprMayJunJulAugSepOctNovDec
Humidity

Line chart showing monthly humidity. Jan: 80%. Feb: 74%. Mar: 77%. Apr: 74%. May: 70%. Jun: 64%. Jul: 64%. Aug: 66%. Sep: 66%. Oct: 63%. Nov: 72%. Dec: 79%.

Monthly Wind Speed

0 15 30 45 60 JanFebMarAprMayJunJulAugSepOctNovDec
Wind SpeedGusts

Bar chart showing monthly wind speed. Jan: 12 km/h . Feb: 14 km/h . Mar: 14 km/h . Apr: 13 km/h . May: 13 km/h . Jun: 13 km/h . Jul: 11 km/h . Aug: 11 km/h . Sep: 12 km/h . Oct: 11 km/h . Nov: 11 km/h . Dec: 11 km/h .

Sunshine

0 3 6 9 12 15 JanFebMarAprMayJunJulAugSepOctNovDec
Sunshine

Sunshine: Jan: 7h. Feb: 9h. Mar: 10h. Apr: 11h. May: 13h. Jun: 13h. Jul: 13h. Aug: 12h. Sep: 11h. Oct: 10h. Nov: 8h. Dec: 7h.

Sea Temperature

20°C 16°C 12°C 8°C swim JanFebMarAprMayJunJulAugSepOctNovDec
Sea Temperatureswim

Line chart showing monthly sea temperature. Jan: 13°C . Feb: 12°C . Mar: 12°C . Apr: 12°C . May: 13°C . Jun: 14°C . Jul: 14°C . Aug: 15°C . Sep: 16°C . Oct: 15°C . Nov: 14°C . Dec: 13°C .

UV Index

0 3 6 8 11 JanFebMarAprMayJunJulAugSepOctNovDec
UV Index

Bar chart showing monthly UV index. Jan: UV 3. Feb: UV 4. Mar: UV 6. Apr: UV 7. May: UV 8. Jun: UV 8. Jul: UV 8. Aug: UV 8. Sep: UV 6. Oct: UV 5. Nov: UV 4. Dec: UV 3.

Monthly Daylight Hours

16h 14h 12h 10h 8h JanFebMarAprMayJunJulAugSepOctNovDec
Daylight12h reference

Monthly Dew Point & Comfort

28°C 24°C 20°C 16°C 12°C 8°C 4°C 0°C -4°C JanFebMarAprMayJunJulAugSepOctNovDec
Dew Point Dry Comfortable Humid Muggy Oppressive

Month-by-Month Weather Table

January
Fair
Temp
15°C / 7°C
Feels Like
14°C / 5°C
Rain
10days (150 mm) Wet
Sun
7.1h Good
Humidity
80% Humid
UV
3.1 Moderate
February
Fair
Temp
16°C / 7°C
Feels Like
15°C / 5°C
Rain
8days (122 mm) Wet
Sun
8.6h Good
Humidity
74% Muggy
UV
3.9 Moderate
March
Good
Temp
17°C / 8°C
Feels Like
16°C / 6°C
Rain
12days (127 mm) Wet
Sun
9.6h Good
Humidity
77% Humid
UV
5.5 High
April
Good
Temp
20°C / 10°C
Feels Like
19°C / 8°C
Rain
5days (34 mm) Good
Sun
11h Excellent
Humidity
74% Muggy
UV
6.9 High
May
Excellent
Temp
22°C / 11°C
Feels Like
22°C / 10°C
Rain
2days (18 mm) Excellent
Sun
12.5h Excellent
Humidity
70% Muggy
UV
7.9 Very High
June best
Excellent
Temp
26°C / 13°C
Feels Like
27°C / 13°C
Rain
0days (0 mm) Excellent
Sun
13.4h Excellent
Humidity
64% Muggy
UV
8.2 Very High
July best
Excellent
Temp
28°C / 15°C
Feels Like
29°C / 15°C
Rain
0days (0 mm) Excellent
Sun
13.2h Excellent
Humidity
64% Muggy
UV
8.3 Very High
August best
Excellent
Temp
28°C / 16°C
Feels Like
29°C / 16°C
Rain
0days (1 mm) Excellent
Sun
12.4h Excellent
Humidity
66% Muggy
UV
7.7 Very High
September best
Excellent
Temp
28°C / 16°C
Feels Like
28°C / 16°C
Rain
1days (5 mm) Excellent
Sun
11.3h Excellent
Humidity
66% Muggy
UV
6.4 High
October best
Excellent
Temp
25°C / 14°C
Feels Like
24°C / 13°C
Rain
2days (31 mm) Excellent
Sun
9.7h Good
Humidity
63% Muggy
UV
5.1 High
November
Good
Temp
19°C / 10°C
Feels Like
18°C / 8°C
Rain
6days (66 mm) Good
Sun
8.2h Good
Humidity
72% Muggy
UV
3.5 Moderate
December
Fair
Temp
16°C / 7°C
Feels Like
14°C / 5°C
Rain
9days (121 mm) Wet
Sun
6.9h Fair
Humidity
79% Humid
UV
2.9 Moderate
Month Temp Feels Like Rain Sun Humidity UV Status Details
January 15°C / 7°C 14°C / 5°C 10days (150 mm) Wet 7.1h Good 80% Humid 3.1 Moderate Fair View Details
February 16°C / 7°C 15°C / 5°C 8days (122 mm) Wet 8.6h Good 74% Muggy 3.9 Moderate Fair View Details
March 17°C / 8°C 16°C / 6°C 12days (127 mm) Wet 9.6h Good 77% Humid 5.5 High Good View Details
April 20°C / 10°C 19°C / 8°C 5days (34 mm) Good 11h Excellent 74% Muggy 6.9 High Good View Details
May 22°C / 11°C 22°C / 10°C 2days (18 mm) Excellent 12.5h Excellent 70% Muggy 7.9 Very High Excellent View Details
June best 26°C / 13°C 27°C / 13°C 0days (0 mm) Excellent 13.4h Excellent 64% Muggy 8.2 Very High Excellent View Details
July best 28°C / 15°C 29°C / 15°C 0days (0 mm) Excellent 13.2h Excellent 64% Muggy 8.3 Very High Excellent View Details
August best 28°C / 16°C 29°C / 16°C 0days (1 mm) Excellent 12.4h Excellent 66% Muggy 7.7 Very High Excellent View Details
September best 28°C / 16°C 28°C / 16°C 1days (5 mm) Excellent 11.3h Excellent 66% Muggy 6.4 High Excellent View Details
October best 25°C / 14°C 24°C / 13°C 2days (31 mm) Excellent 9.7h Good 63% Muggy 5.1 High Excellent View Details
November 19°C / 10°C 18°C / 8°C 6days (66 mm) Good 8.2h Good 72% Muggy 3.5 Moderate Good View Details
December 16°C / 7°C 14°C / 5°C 9days (121 mm) Wet 6.9h Fair 79% Humid 2.9 Moderate Fair View Details

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Frequently Asked Questions

The best months to visit Cupertino are June, July, August, September, October, when temperatures are comfortable and rainfall is at its lowest. This is based on 10-year climate averages for Cupertino, scoring temperature, rainfall, humidity, and sunshine hours.
The hottest month in Cupertino is August, with average daytime highs of 28°C (83°F). Plan outdoor activities for early morning or late afternoon if visiting during this period.
The coldest month in Cupertino is January, with average overnight lows of 7°C (45°F). Pack warm layers and expect shorter daylight hours during this period.
The wettest month in Cupertino is January, averaging 150mm of precipitation across 10 rainy days. An umbrella or waterproof jacket is essential.
The rainy season in Cupertino runs through March, January, with the heaviest rainfall in March. Based on 10-year averages for Cupertino.
Cupertino receives approximately 124 sunshine hours per year. The sunniest month is June with around 13 hours. Based on climate data for Cupertino.
The least favorable months to visit Cupertino are January, February, December, primarily due to less favorable weather conditions. For the best conditions, consider June, July, August, September, October instead.
The annual average UV index in Cupertino is 6, classified as high. Standard sun protection (sunscreen, hat) is recommended during prolonged outdoor exposure.
Average humidity in Cupertino is 71%, classified as moderate. Humidity levels are generally comfortable and should not affect outdoor activities for most people.
Sea temperatures in Summer average 14°C (57°F), which most swimmers will find too cold without a wetsuit.
Average wind speeds in Cupertino are 12 km/h (7 mph). The windiest month is February with peak winds reaching 14 km/h (9 mph) (gusts up to 42 km/h / 26 mph).
Cupertino averages 11 clear-sky days per month with overall cloud cover around 41%. The clearest skies occur in July.
The annual average dew point in Cupertino is 11°C (52°F), which feels pleasant with low humidity. Outdoor activities are comfortable year-round from a humidity standpoint.
Cupertino has a Warm-Summer Mediterranean climate, classified as Csb under the Köppen system. Temperate climates have mild winters and warm summers, with rainfall spread across the year and four distinct seasons.
The 'feels like' temperature in Cupertino ranges from 10°C (50°F) to 21°C (70°F) on average. The 'feels like' temperature closely matches the actual temperature throughout most of the year.
Yes, June is a great time to visit Cupertino. It earns a climate score of 9.5/10 with Excellent.
For June in Cupertino, pack Breathable clothing, Sunscreen (SPF 30+), Sun hat, Sunglasses, Comfortable walking shoes. With average highs of 26°C (79°F) and 0 rainy days, these essentials will keep you comfortable.

Data Source

Climate data derived from ERA5 reanalysis (ECMWF), averaged over 2016–2025. Sea surface temperature from marine reanalysis data. Climate scores and seasonal estimates are computed by WorldStats.

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