Berkeley, United States — Weather in September 2026

Climate Overview

Berkeley, United States in September has warm conditions, with highs averaging 27.3°C (81°F). Rain is rare, falling on about 0 days this month. Temperatures drop noticeably between day and night. Sea temperature averages 21°C (70°F).

This month falls at the beginning of Autumn.

Temperatures remain fairly steady throughout September, with daily highs around 28°C (82°F).

Rainfall is heaviest during the middle of the month, while the first third tends to be drier.

Expect around 11.7h of sunshine at the start of September, decreasing to 10.6h by the end.

The warmest days tend to fall around the 7th, averaging 29.5°C (85°F).

Temperatures begin dropping heading into October.

Monthly September Averages

Temperature

27°C / 14°C

Feels Like

27°C / 14°C

Rain

0 days · 2 mm

Sunshine

11.3h / day

Humidity

68% — Humid

Wind

16 km/h

Wind Direction

WSW (252°)

Gusts

38 km/h

Daylight

12.4 h

Cloud Cover

36%

Clear Sky Days

7.9

UV Index

6.4 — High

Sea Temperature

21°C

Dew Point

15°C — Comfortable

Moon Phase

Waxing Crescent · 11%

Climate Charts

Daily averages based on historical data (2016–2025)

Daily Temperature

HighLow

Daily Precipitation

Rainfall

Daily Sunshine

Sunshine

Daily Wind Speed

Wind Speed

Sun Position

Sunrise 06:52

Daylight 12.4h

Sunset 19:19

What to Expect

Daytime temperatures around 27°C (81°F) are ideal for full-day outdoor exploration.

Rain is uncommon in this month, so most days stay dry from morning through evening.

Recent yearly records for September have stayed close to the long-run average.

Compare Months

2days (14 mm) Excellent

0days (1 mm) Excellent

0days (0 mm) Excellent

0days (0 mm) Excellent

0days (2 mm) Excellent

2days (23 mm) Excellent

Month	Temp	Feels Like	Rain	Sun	Humidity	UV	Status	Details
January	14°C / 6°C	13°C / 4°C	10days (103 mm) Wet	6.8h Fair	82% Humid	2.9 Moderate	Fair	View Details
February	16°C / 6°C	14°C / 4°C	7days (81 mm) Good	8.4h Good	75% Muggy	3.8 Moderate	Fair	View Details
March	17°C / 7°C	15°C / 5°C	11days (86 mm) Wet	9.4h Good	76% Humid	5.4 High	Good	View Details
April	20°C / 9°C	19°C / 7°C	4days (25 mm) Good	11h Excellent	71% Muggy	6.9 High	Good	View Details
May	23°C / 11°C	22°C / 9°C	2days (14 mm) Excellent	12.6h Excellent	66% Muggy	7.9 Very High	Excellent	View Details
June best	26°C / 13°C	26°C / 11°C	0days (1 mm) Excellent	13.4h Excellent	63% Muggy	8.2 Very High	Excellent	View Details
July best	27°C / 13°C	26°C / 12°C	0days (0 mm) Excellent	13.2h Excellent	68% Muggy	8.2 Very High	Excellent	View Details
August best	27°C / 14°C	27°C / 14°C	0days (0 mm) Excellent	12.4h Excellent	69% Muggy	7.6 Very High	Excellent	View Details
September best	27°C / 14°C	27°C / 14°C	0days (2 mm) Excellent	11.3h Excellent	68% Muggy	6.4 High	Excellent	View Details
October best	25°C / 12°C	23°C / 11°C	2days (23 mm) Excellent	9.6h Good	64% Muggy	5 Moderate	Excellent	View Details
November	18°C / 9°C	17°C / 7°C	6days (49 mm) Good	8h Good	74% Muggy	3.4 Moderate	Good	View Details
December	14°C / 6°C	13°C / 4°C	9days (92 mm) Wet	6.5h Fair	81% Humid	2.7 Moderate	Fair	View Details

What to Wear

Summer clothing like shorts, t-shirts, and sundresses will be comfortable. Bring a light cardigan for air-conditioned spaces.

Temperatures drop significantly at night, so pack layers you can add or remove throughout the day.

Packing List

Breathable clothingSunscreen (SPF 30+)Sun hatSunglassesComfortable walking shoes

Frequently Asked Questions

Expand all

Is September a good time to visit Berkeley?

September is typically excellent for visiting Berkeley, with average highs of 27°C (81°F) and around 0 rainy days. Berkeley, United States in September has warm conditions, with highs averaging 27.3°C (81°F). Rain is rare, falling on a

Does it rain a lot in Berkeley in September?

Berkeley typically sees around 0 rainy days in September with 2 mm (0.1 in) of total rainfall. An umbrella should suffice.

Does it get cold at night in Berkeley in September?

Evenings in Berkeley during September are mild at 14°C (57°F). A light cardigan is usually enough.

What should I pack for Berkeley in September?

With highs of 27°C (81°F) and lows of 14°C (57°F) in September, we recommend: Breathable clothing, Sunscreen (SPF 30+), Sun hat, Sunglasses, Comfortable walking shoes. Comfortable walking shoes are essential.

Is September among the best months weather-wise in Berkeley?

Yes, September offers some of the best weather conditions in Berkeley with comfortable temperatures and lower chances of rain.

What is the UV index in Berkeley in September?

The average UV index in Berkeley during September is 6 (high). Wear sunscreen SPF 30+, a hat, and sunglasses. Limit direct sun exposure between 10 AM and 4 PM.

How many hours of daylight are there in Berkeley in September?

Berkeley gets approximately 12 hours of daylight per day in September, with around 11 hours of sunshine.

Does it snow in Berkeley in September?

Snow is uncommon in Berkeley during September based on 10-year climate averages.

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