September
Other strong months: August and October
98/100 weather score
United States · 1991–2020
Best time to visit
Alameda
For Alameda, September has the most comfortable weather in our climate comparison. Typical daytime highs are 23.7°C, nights average 14.3°C, and rainfall totals about 3 mm. Figures use measured 1991–2020 normals from the nearest eligible NOAA station.
Best all-round monthSeptember
Typical daytime high23.7°C
Typical night-time low14.3°C
September rainfall3 mm
September
Other strong months: August and July
65/100 weather score
May
Other strong months: April and June
96/100 weather score
Make the answer personal
Choose the weather
that suits you.
Set the daytime temperature and rainfall you are comfortable with. We will show only the months that meet every choice, using the measured 1991–2020 averages below.
9 months fit your choices for Alameda
December has the lowest comfort score at 41 out of 100, compared with September at 98. The main reason is that days reach only 15.2°C, 9° below the 24°C the score treats as ideal.
Quick answers
Planning a trip to Alameda?
These answers come from the same measured monthly climate record shown on this page.
When is the best time to visit Alameda?
September is the strongest all-round choice in our temperature-and-rainfall comparison, with a typical daytime high of 23.7°C and 3 mm of rain.
What is the hottest month in Alameda?
September is hottest in this record, with a typical daytime high of 23.7°C and a night-time low of 14.3°C.
Which month has the least rain?
July has the lowest monthly rainfall total at 0 mm.
Is this a weather forecast?
No. These are long-term measured averages from 1991–2020. Check a current forecast before you travel.
Month by month
See how the weather
changes through the year.
The bars combine daytime temperature, night-time temperature and rainfall. The figures are measured historical averages, not a forecast for a particular trip.
| Month | Day | Night | Rain | Wet days | Sea | Daylight | Comfort | Coverage |
|---|---|---|---|---|---|---|---|---|
| January | 15.4°C | 7.5°C | 108 mm | 9 | 11.6°C | 9 h 49 | 42 | Strong coverage |
| February | 16.8°C | 8.6°C | 107 mm | 8.4 | 11.9°C | 10 h 44 | 50 | Strong coverage |
| March | 18.2°C | 9.6°C | 80 mm | 7.9 | 12.0°C | 11 h 50 | 60 | Strong coverage |
| April | 19°C | 10.4°C | 33 mm | 4.5 | 11.5°C | 13 h 07 | 74 | Strong coverage |
| May | 20.2°C | 11.9°C | 20 mm | 2.9 | 11.7°C | 14 h 11 | 82 | Strong coverage |
| June | 22°C | 13.2°C | 5 mm | 0.6 | 12.1°C | 14 h 46 | 90 | Strong coverage |
| July | 21.9°C | 13.9°C | 0 mm | 0 | 13.4°C | 14 h 32 | 91 | Strong coverage |
| August | 22.8°C | 14.5°C | 1 mm | 0.2 | 14.2°C | 13 h 37 | 95 | Strong coverage |
| September | 23.7°C | 14.3°C | 3 mm | 0.5 | 14.4°C | 12 h 23 | 98 | Strong coverage |
| October | 22.6°C | 12.9°C | 29 mm | 2.5 | 13.7°C | 11 h 09 | 92 | Strong coverage |
| November | 18.6°C | 9.8°C | 62 mm | 5.2 | 12.9°C | 10 h 05 | 67 | Strong coverage |
| December | 15.2°C | 7.5°C | 119 mm | 8.6 | 12.0°C | 9 h 34 | 41 | Strong coverage |
What has changed
Recent daytime highs are
0.6°C warmer in Alameda.
Each bar shows the difference between the 2011–2025 average daytime high and the 1961–1990 average for the same month at the same station. A blank month does not have enough older observations for a reliable comparison.
Jan
+2.6
Feb
+1.0
Mar
+0.6
Apr
+0.2
May
-0.6
Jun
-0.2
Jul
-1.0
Aug
+0.1
Sep
0.0
Oct
+1.3
Nov
+1.6
Dec
+2.0
| Month | Record high | Record low | Wettest day | Wettest / driest month | Years |
|---|---|---|---|---|---|
| January | 26.1°C18 Jan 2021 | -1.1°C30 Jan 1975 | 120 mm4 Jan 1982 | 316 mm1998 · driest 0 mm in 2015 | 54 |
| February | 28.3°C27 Feb 2026 | -1.7°C5 Feb 1976 | 78 mm13 Feb 2000 | 385 mm1998 · driest 0 mm in 2020 | 51 |
| March | 32.8°C20 Mar 2026 | 1.1°C3 Mar 1976 | 73 mm31 Mar 1982 | 250 mm1983 · driest 1 mm in 1988 | 53 |
| April | 36.1°C29 Apr 1981 | 2.8°C1 Apr 1976 | 53 mm1 Apr 1974 | 105 mm1982 · driest 0 mm in 1977 | 52 |
| May | 40.6°C12 May 1976 | 6.1°C5 May 1975 | 38 mm27 May 1990 | 76 mm1998 · driest 0 mm in 2014 | 52 |
| June | 40.0°C26 Jun 1973 | 8.9°C3 Jun 1976 | 35 mm4 Jun 2011 | 69 mm2011 · driest 0 mm in 1977 | 50 |
| July | 39.4°C13 Jul 1972 | 10.6°C22 Jul 2008 | 24 mm8 Jul 1974 | 30 mm1974 · driest 0 mm in 2013 | 51 |
| August | 37.8°C14 Aug 2020 | 10.0°C17 Aug 1977 | 25 mm19 Aug 1997 | 32 mm1997 · driest 0 mm in 1985 | 53 |
| September | 42.8°C14 Sep 1971 | 8.9°C28 Sep 1986 | 20 mm16 Sep 1989 | 39 mm1986 · driest 0 mm in 2011 | 52 |
| October | 39.4°C2 Oct 1980 | 6.1°C6 Oct 2007 | 109 mm24 Oct 2021 | 176 mm2021 · driest 0 mm in 2003 | 53 |
| November | 28.9°C5 Nov 2012 | 2.2°C29 Nov 1975 | 105 mm5 Nov 1994 | 246 mm1973 · driest 5 mm in 2020 | 54 |
| December | 23.9°C7 Dec 1979 | -3.3°C9 Dec 1972 | 121 mm31 Dec 2022 | 334 mm2022 · driest 0 mm in 1989 | 52 |
| Month | Days 25°C+ | Days 30°C+ | Heavy rain (10 mm+) |
|---|---|---|---|
| January | <1 | 0 | 3 |
| February | <1 | 0 | 4 |
| March | 2 | 0 | 3 |
| April | 3 | <1 | 1 |
| May | 4 | 1 | <1 |
| June | 6 | 1 | <1 |
| July | 5 | <1 | 0 |
| August | 7 | 1 | 0 |
| September | 10 | 3 | <1 |
| October | 9 | 2 | <1 |
| November | 2 | 0 | 2 |
| December | 0 | 0 | 4 |
| Month | Dry days reaching 20°C | Wet days | Days with heavy rain | Weeks with 3+ wet days | Typical high by year |
|---|---|---|---|---|---|
| January | 7% | 27% | 11% | 33% | 13.0–16.9°C |
| February | 18% | 30% | 13% | 40% | 15.0–18.5°C |
| March | 26% | 27% | 11% | 29% | 15.5–20.0°C |
| April | 36% | 15% | 4% | 12% | 17.7–20.9°C |
| May | 48% | 7% | 1% | 5% | 18.4–22.6°C |
| June | 70% | 2% | <1% | <1% | 20.1–23.5°C |
| July | 80% | <1% | <1% | 0% | 20.8–24.0°C |
| August | 87% | <1% | <1% | <1% | 21.6–24.4°C |
| September | 84% | 3% | <1% | 1% | 21.4–26.4°C |
| October | 69% | 9% | 3% | 8% | 20.9–24.4°C |
| November | 29% | 20% | 8% | 24% | 16.3–19.9°C |
| December | 3% | 27% | 11% | 36% | 12.8–16.5°C |
A dry day reaching 20°C records under 1 mm of rain. A wet day records at least 1 mm, while a heavy-rain day records at least 10 mm. The weekly figure is the share of seven-day periods containing three or more wet days. The final column shows the middle 80% of average daytime highs recorded for that month in individual years; a wider range means conditions have varied more from one year to another.
The evidence behind this page
Where these figures
come from.
- Place identity
- GeoNames 5322737
- NOAA station
- USC00046336 · OAKLAND MUSEUM
- Station distance
- 3.1 km from the place centre
- Climate period
- 1991–2020
- Minimum month coverage
- 25 usable years
- Daylight
- Calculated from latitude 37.77°, mid-month, sunrise to sunset including refraction. Not a station measurement.
- Sea temperature
- NOAA OISST v2.1 1991–2020 monthly climatology, nearest open water 34 km from the place centre. A sheltered bay can run warmer than the open sea it is measured from.
- Important limit
- Historical climate is not a forecast. Nearby stations can miss mountains, coasts, and local microclimates.
Next step
Choose your month.
Then plan the details.
The weather comparison for Alameda is based on climate evidence, not payments from travel companies. Flight, accommodation and activity links will be clearly labelled when they are added; there are no booking offers on this page today.
How travel partnerships will work