San Mateo weather in September 2025

The temperatures in San Mateo in September are comfortable with low of 15°C and and high up to 23°C.

You can expect up to 3 rainy days in San Mateo during the month of September.

Our weather forecast can give you a great sense of what weather to expect in San Mateo in September 2025.

If you’re planning to visit San Mateo in the near future, we highly recommend that you review the 14 day weather forecast for San Mateo before you arrive.

Temperatures

23° / 15°

Rainy Days

Snowy Days

Dry Days

Rainfall

Sun Hours

11.1

Hrs

Sun	Mon	Tue	Wed	Thu	Fri	Sat
	1 21° /13°	2 21° /13°	3 23° /13°	4 24° /13°	5 24° /14°	6 25° /14°
7 23° /13°	8 24° /14°	9 22° /12°	10 21° /12°	11 21° /14°	12 20° /13°	13 21° /13°
14 20° /12°	15 20° /13°	16 19° /13°	17 18° /13°	18 18° /13°	19 19° /13°	20 19° /13°
21 20° /13°	22 20° /12°	23 22° /12°	24 23° /14°	25 21° /13°	26 21° /14°	27 23° /12°
28 20° /13°	29 21° /13°	30 23° /13°

Explore the weather in San Mateo in other months

San Mateo annual weather

Month	Temperatures	Rainy Days	Dry Days	Rainfall	Weather	More details
January	15° / 9°	6	25	92 mm	Good	San Mateo in January
February	15° / 9°	5	23	82 mm	Good	San Mateo in February
March	16° / 9°	7	24	85 mm	Ok	San Mateo in March
April	17° / 10°	3	27	35 mm	Good	San Mateo in April
May	18° / 11°	2	29	15 mm	Good	San Mateo in May
June	21° / 13°	1	29	4 mm	Good	San Mateo in June
July	22° / 14°	0	31	1 mm	Good	San Mateo in July
August	23° / 15°	0	31	0 mm	Perfect	San Mateo in August
September	23° / 15°	0	30	3 mm	Perfect	San Mateo in September
October	21° / 14°	2	29	28 mm	Good	San Mateo in October
November	17° / 11°	4	26	51 mm	Good	San Mateo in November
December	14° / 9°	6	25	101 mm	Good	San Mateo in December

Temperatures in San Mateo in September

Rain in San Mateo in September

Weather in San Mateo in September - FAQ

What is the average temperature in San Mateo in September?

The average temperature in San Mateo in September is 15/23° C.

What is the chance of rain in San Mateo in September?

On average, there are 0 rainy days in San Mateo during September.

Weather wise, is September a good time to visit San Mateo?

The weather in San Mateo in September is perfect.

Can it snow in San Mateo in September?

On average, there are 0 snowy days in San Mateo in September.

More about the weather in San Mateo