September
September · October · August
96climate match
United States · 1991–2020
Best time to visit
Imperial Beach.
September leads for comfortable weather in Imperial Beach: typically 24°C by day, 17.2°C at night, with 3 mm of rain. Based on measured 1991–2020 NOAA station history.
Best comfortSeptember
Typical high24°C
Typical low17.2°C
Rain in September3 mm
August
August · July · September
77climate match
April
April · November · March
95climate match
The weakest month is January, scoring 69 against September’s 96 — days reach only 18.8°C, 5° below the 24°C the score treats as ideal, and nights drop to 8.8°C.
Month by month
The whole year,
without the guesswork.
The bars show the comfort score. Day and night temperatures come from daily observed highs and lows; rain is the historical monthly estimate.
Jan
6918.8° / 8.8°
Feb
7118.5° / 9.4°
Mar
7418.7° / 10.7°
Apr
8019.5° / 11.9°
May
8520.1° / 14.1°
Jun
8821° / 16.1°
Jul
9223.2° / 17.8°
Aug
9423.9° / 18.1°
Sep
9624° / 17.2°
Oct
9522.9° / 14°
Nov
8421.4° / 10.7°
Dec
7018.5° / 8.3°
| Month | Day | Night | Rain | Wet days | Sea | Daylight | Comfort | Coverage |
|---|---|---|---|---|---|---|---|---|
| January | 18.8°C | 8.8°C | 44 mm | 4 | 15.3°C | 10 h 13 | 69 | Good coverage |
| February | 18.5°C | 9.4°C | 35 mm | 4.2 | 15.1°C | 10 h 58 | 71 | Good coverage |
| March | 18.7°C | 10.7°C | 36 mm | 3.8 | 15.5°C | 11 h 53 | 74 | Good coverage |
| April | 19.5°C | 11.9°C | 7 mm | 1.5 | 16.1°C | 12 h 56 | 80 | Good coverage |
| May | 20.1°C | 14.1°C | 4 mm | 0.6 | 17.3°C | 13 h 49 | 85 | Good coverage |
| June | 21°C | 16.1°C | 0 mm | 0 | 18.6°C | 14 h 17 | 88 | Good coverage |
| July | 23.2°C | 17.8°C | 3 mm | 0.2 | 20.2°C | 14 h 06 | 92 | Good coverage |
| August | 23.9°C | 18.1°C | 0 mm | 0.1 | 21.0°C | 13 h 21 | 94 | Good coverage |
| September | 24°C | 17.2°C | 3 mm | 0.4 | 20.5°C | 12 h 20 | 96 | Good coverage |
| October | 22.9°C | 14°C | 2 mm | 0.4 | 19.3°C | 11 h 19 | 95 | Good coverage |
| November | 21.4°C | 10.7°C | 9 mm | 1.8 | 17.5°C | 10 h 26 | 84 | Good coverage |
| December | 18.5°C | 8.3°C | 22 mm | 2.9 | 16.0°C | 10 h 01 | 70 | Good coverage |
What has changed
Imperial Beach runs +1.4°C
on the 1961–1990 baseline.
Each bar compares the 2011–2025 daytime average for that month against the same month in 1961–1990, measured at the same station. Months where the older record is too thin to compare are left blank.
Jan
+1.7
Feb
+1.7
Mar
+1.4
Apr
+1.4
May
+0.8
Jun
+0.8
Jul
+1.3
Aug
+0.8
Sep
+1.9
Oct
+2.0
Nov
+2.1
Dec
+1.5
| Month | Record high | Record low | Wettest day | Wettest / driest month | Years |
|---|---|---|---|---|---|
| January | 30.0°C16 Jan 1976 | -3.3°C7 Jan 1971 | 58 mm7 Jan 1993 | 190 mm1993 · driest 0 mm in 2015 | 60 |
| February | 33.9°C16 Feb 2016 | 0.0°C6 Feb 1946 | 113 mm2 Feb 1988 | 131 mm1988 · driest 0 mm in 1946 | 61 |
| March | 30.0°C16 Mar 2015 | 0.6°C2 Mar 1971 | 52 mm24 Mar 2010 | 138 mm1983 · driest 0 mm in 1956 | 63 |
| April | 30.0°C19 Apr 2009 | 1.1°C4 Apr 1945 | 32 mm8 Apr 1965 | 82 mm1965 · driest 0 mm in 1946 | 65 |
| May | 29.4°C16 May 2008 | 6.1°C30 May 2011 | 26 mm8 May 1977 | 29 mm1977 · driest 0 mm in 1973 | 65 |
| June | 32.2°C28 Jun 1980 | 7.8°C1 Jun 1971 | 20 mm8 Jun 1990 | 39 mm1990 · driest 0 mm in 1997 | 60 |
| July | 33.3°C22 Jul 2015 | 11.1°C7 Jul 1948 | 40 mm24 Jul 2008 | 40 mm2008 · driest 0 mm in 1980 | 61 |
| August | 33.3°C27 Aug 2008 | 9.4°C31 Aug 2010 | 41 mm20 Aug 2023 | 53 mm1977 · driest 0 mm in 2016 | 58 |
| September | 35.0°C10 Sep 2008 | 8.9°C30 Sep 2013 | 28 mm10 Sep 1976 | 57 mm1963 · driest 0 mm in 1961 | 61 |
| October | 36.7°C25 Oct 2017 | 1.7°C29 Oct 1971 | 16 mm30 Oct 1996 | 44 mm1957 · driest 0 mm in 2002 | 60 |
| November | 37.2°C4 Nov 1976 | -1.0°C25 Nov 2007 | 73 mm25 Nov 1985 | 163 mm1965 · driest 0 mm in 1956 | 61 |
| December | 30.6°C30 Dec 1980 | -1.1°C8 Dec 1978 | 58 mm27 Dec 1984 | 170 mm1984 · driest 0 mm in 2011 | 61 |
| Month | Days 25°C+ | Days 30°C+ | Heavy rain (10 mm+) |
|---|---|---|---|
| January | 2 | 0 | 1 |
| February | 2 | <1 | <1 |
| March | 1 | <1 | 1 |
| April | 2 | 0 | <1 |
| May | 1 | 0 | <1 |
| June | <1 | <1 | 0 |
| July | 5 | <1 | <1 |
| August | 9 | <1 | 0 |
| September | 8 | <1 | <1 |
| October | 7 | 2 | 0 |
| November | 4 | 1 | <1 |
| December | 1 | <1 | <1 |
The best month has moved. On the 1961–1990 numbers the strongest month here was September (scoring 94); on 2011–2025 it is October (98). Both are scored the same way, from the same station — only the climate underneath changed.
| Month | Warm & dry days | Wet days | Washouts | Week with 3+ wet days | Daytime mean has ranged |
|---|---|---|---|---|---|
| January | 25% | 14% | 4% | 13% | 16.1–20.3°C |
| February | 23% | 13% | 4% | 11% | 16.3–20.3°C |
| March | 19% | 14% | 4% | 13% | 16.5–20.0°C |
| April | 30% | 8% | 1% | 5% | 17.5–20.7°C |
| May | 45% | 3% | <1% | <1% | 18.3–21.2°C |
| June | 70% | <1% | <1% | 0% | 19.0–22.4°C |
| July | 94% | <1% | <1% | 0% | 20.9–24.6°C |
| August | 99% | <1% | <1% | <1% | 22.0–25.1°C |
| September | 96% | 2% | <1% | <1% | 21.7–25.2°C |
| October | 82% | 3% | <1% | 1% | 20.5–24.4°C |
| November | 48% | 9% | 3% | 8% | 18.3–22.9°C |
| December | 25% | 11% | 3% | 7% | 16.3–20.8°C |
A warm and dry day reaches 20°C with under 1 mm of rain; a wet day gets 1 mm or more; a washout gets 10 mm or more. The week column is the share of seven-day stretches in that month, across the station’s whole daily record, that contained three or more wet days — the odds a week-long trip is rained on repeatedly, counted rather than modelled. The last column is the 10th to 90th percentile of that month’s daytime average across individual years: a narrow band means the average is what you will get, a wide one means the average is a midpoint between years that felt quite different.
The evidence behind this page
Nearby, measured,
and named.
- Place identity
- GeoNames 5359054
- NOAA station
- USW00093115 · IMPERIAL BEACH REAM FLD NAS
- Station distance
- 1.8 km from the place centre
- Climate period
- 1991–2020
- Minimum month coverage
- 18 usable years
- Daylight
- Calculated from latitude 32.58°, mid-month, sunrise to sunset including refraction. Not a station measurement.
- Sea temperature
- NOAA OISST v2.1 1991–2020 monthly climatology, nearest open water 5 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.