Thousand Oaks, United States — Weather in September 2026

Climate Overview

Thousand Oaks, United States in September has hot conditions, with highs reaching 28.8°C (84°F) and afternoons the warmest part of the day. Rain is rare, falling on about 1 days this month. Temperatures drop noticeably between day and night. Sea temperature averages 21.2°C (70°F).

This month falls at the beginning of Autumn.

Daily highs in September gradually drop from around 31°C (88°F) at the start to 28°C (82°F) by month's end.

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

Expect around 11.8h of sunshine at the start of September, decreasing to 11.0h by the end.

The warmest days tend to fall around the 6th, averaging 31.9°C (89°F).

Temperatures begin dropping heading into October.

Monthly September Averages

Temperature

29°C / 18°C

Feels Like

30°C / 20°C

Rain

1 days · 6 mm

Sunshine

11.4h / day

Humidity

66% — Muggy

Wind

11 km/h

Wind Direction

SW (214°)

Gusts

34 km/h

Daylight

12.4 h

Cloud Cover

26%

Clear Sky Days

15.8

UV Index

7 — High

Sea Temperature

21°C

Dew Point

17°C — Humid

Moon Phase

Waxing Crescent · 11%

Climate Charts

Daily averages based on historical data (2016–2025)

Daily Temperature

High Low

Daily Precipitation

Rainfall

Daily Sunshine

Sunshine

Daily Wind Speed

Wind Speed

Sun Position

Sunrise 06:39

Daylight 12.4h

Sunset 19:02

What to Expect

Daytime temperatures around 29°C (84°F) are ideal for full-day outdoor exploration.

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

1 of the last 5 yearly records were warmer than this month's long-run average.

Compare Months

3days (18 mm) Excellent

2days (10 mm) Excellent

0days (1 mm) Excellent

0days (1 mm) Excellent

1days (9 mm) Excellent

1days (6 mm) Excellent

2days (12 mm) Excellent

3days (33 mm) Excellent

Month	Temp	Feels Like	Rain	Sun	Humidity	UV	Status	Details
January	18°C / 7°C	16°C / 4°C	6days (91 mm) Good	8.2h Good	68% Muggy	3.7 Moderate	Good	View Details
February	19°C / 7°C	17°C / 5°C	5days (80 mm) Good	9h Good	64% Muggy	4.4 Moderate	Good	View Details
March	19°C / 8°C	18°C / 6°C	8days (83 mm) Wet	10.1h Excellent	71% Muggy	6 High	Good	View Details
April best	22°C / 11°C	22°C / 10°C	3days (18 mm) Excellent	11.7h Excellent	66% Muggy	7.2 Very High	Excellent	View Details
May best	23°C / 13°C	24°C / 13°C	2days (10 mm) Excellent	12.7h Excellent	70% Muggy	7.6 Very High	Excellent	View Details
June best	27°C / 16°C	28°C / 17°C	0days (1 mm) Excellent	13.3h Excellent	68% Muggy	8.2 Very High	Excellent	View Details
July	30°C / 19°C	32°C / 21°C	0days (1 mm) Excellent	13.2h Excellent	65% Muggy	8.5 Very High	Excellent	View Details
August	30°C / 20°C	32°C / 22°C	1days (9 mm) Excellent	12.3h Excellent	66% Muggy	7.9 Very High	Excellent	View Details
September best	29°C / 18°C	30°C / 20°C	1days (6 mm) Excellent	11.4h Excellent	66% Muggy	7 High	Excellent	View Details
October best	26°C / 15°C	26°C / 14°C	2days (12 mm) Excellent	10.3h Excellent	60% Moderate	5.6 High	Excellent	View Details
November	22°C / 11°C	20°C / 9°C	3days (33 mm) Excellent	8.9h Good	58% Moderate	4 Moderate	Good	View Details
December	19°C / 8°C	17°C / 5°C	5days (80 mm) Good	7.8h Good	65% Muggy	3.3 Moderate	Good	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 hatSunglassesSandals

Frequently Asked Questions

Expand all

Is September a good time to visit Thousand Oaks?

September is typically excellent for visiting Thousand Oaks, with average highs of 29°C (84°F) and around 1 rainy days. Thousand Oaks, United States in September has hot conditions, with highs reaching 28.8°C (84°F) and afternoons the warme

Does it rain a lot in Thousand Oaks in September?

Thousand Oaks typically sees around 1 rainy days in September with 6 mm (0.2 in) of total rainfall. An umbrella should suffice.

Does it get cold at night in Thousand Oaks in September?

Evenings in Thousand Oaks during September are mild at 18°C (65°F). A light cardigan is usually enough.

What should I pack for Thousand Oaks in September?

With highs of 29°C (84°F) and lows of 18°C (65°F) in September, we recommend: Breathable clothing, Sunscreen (SPF 30+), Sun hat, Sunglasses, Sandals. Comfortable walking shoes are essential.

Is September among the best months weather-wise in Thousand Oaks?

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

What is the UV index in Thousand Oaks in September?

The average UV index in Thousand Oaks during September is 7 (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 Thousand Oaks in September?

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

Does it snow in Thousand Oaks in September?

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

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