October
October · September · August
92climate match
United States · 1991–2020
Best time to visit
Costa Mesa.
October leads for comfortable weather in Costa Mesa: typically 22°C by day, 15.8°C at night, with 9 mm of rain. Based on measured 1991–2020 NOAA station history.
Best comfortOctober
Typical high22°C
Typical low15.8°C
Rain in October9 mm
August
August · September · July
75climate match
November
November · December · April
96climate match
The weakest month is February, scoring 64 against October’s 92 — days reach only 17.4°C, 7° below the 24°C the score treats as ideal.
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
6617.8° / 10.2°
Feb
6417.4° / 10.6°
Mar
7317.7° / 11.8°
Apr
7718.3° / 12.8°
May
8419.2° / 14.7°
Jun
8520.2° / 16.3°
Jul
8822° / 18.1°
Aug
9022.9° / 18.5°
Sep
9122.8° / 17.9°
Oct
9222° / 15.8°
Nov
8220° / 12.5°
Dec
7017.9° / 10.1°
| Month | Day | Night | Rain | Wet days | Sea | Daylight | Comfort | Coverage |
|---|---|---|---|---|---|---|---|---|
| January | 17.8°C | 10.2°C | 56 mm | 5 | 15.1°C | 10 h 09 | 66 | Strong coverage |
| February | 17.4°C | 10.6°C | 61 mm | 5.3 | 15.0°C | 10 h 56 | 64 | Strong coverage |
| March | 17.7°C | 11.8°C | 33 mm | 3.8 | 15.2°C | 11 h 52 | 73 | Strong coverage |
| April | 18.3°C | 12.8°C | 13 mm | 2.1 | 15.7°C | 12 h 58 | 77 | Strong coverage |
| May | 19.2°C | 14.7°C | 5 mm | 0.9 | 17.0°C | 13 h 53 | 84 | Strong coverage |
| June | 20.2°C | 16.3°C | 2 mm | 0.1 | 18.5°C | 14 h 22 | 85 | Strong coverage |
| July | 22°C | 18.1°C | 1 mm | 0.2 | 20.2°C | 14 h 11 | 88 | Strong coverage |
| August | 22.9°C | 18.5°C | 0 mm | 0 | 20.7°C | 13 h 24 | 90 | Strong coverage |
| September | 22.8°C | 17.9°C | 2 mm | 0.3 | 20.5°C | 12 h 20 | 91 | Strong coverage |
| October | 22°C | 15.8°C | 9 mm | 1.3 | 19.3°C | 11 h 17 | 92 | Strong coverage |
| November | 20°C | 12.5°C | 16 mm | 2.4 | 17.6°C | 10 h 22 | 82 | Strong coverage |
| December | 17.9°C | 10.1°C | 41 mm | 4.1 | 15.8°C | 9 h 56 | 70 | Strong coverage |
What has changed
Costa Mesa runs +0.3°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
+0.5
Feb
-0.2
Mar
+0.2
Apr
+0.1
May
0.0
Jun
+0.1
Jul
+0.1
Aug
+0.4
Sep
+0.9
Oct
+0.6
Nov
+0.6
Dec
+0.3
| Month | Record high | Record low | Wettest day | Wettest / driest month | Years |
|---|---|---|---|---|---|
| January | 30.6°C11 Jan 1983 | -1.7°C22 Jan 1937 | 91 mm21 Jan 2017 | 281 mm1995 · driest 0 mm in 1976 | 103 |
| February | 32.8°C10 Feb 2022 | -0.6°C4 Feb 1971 | 97 mm24 Feb 1969 | 286 mm1998 · driest 0 mm in 1961 | 102 |
| March | 32.8°C14 Mar 1951 | 0.6°C2 Mar 1953 | 61 mm1 Mar 1978 | 197 mm1983 · driest 0 mm in 1956 | 103 |
| April | 38.3°C7 Apr 2022 | 2.8°C15 Apr 1921 | 63 mm7 Apr 1958 | 128 mm1965 · driest 0 mm in 1979 | 101 |
| May | 35.0°C13 May 2014 | 3.9°C1 May 2000 | 31 mm22 May 1921 | 69 mm1921 · driest 0 mm in 1963 | 105 |
| June | 38.9°C15 Jun 1981 | 5.6°C2 Jun 1923 | 21 mm5 Jun 1993 | 25 mm1934 · driest 0 mm in 1954 | 105 |
| July | 31.1°C25 Jul 2006 | 7.2°C15 Jul 1929 | 3 mm8 Jul 1992 | 7 mm1992 · driest 0 mm in 1967 | 103 |
| August | 34.4°C31 Aug 1955 | 10.6°C30 Aug 1929 | 45 mm21 Aug 2023 | 65 mm2023 · driest 0 mm in 2025 | 103 |
| September | 41.7°C26 Sep 1963 | 7.2°C9 Sep 1929 | 70 mm25 Sep 1939 | 80 mm1939 · driest 0 mm in 1994 | 101 |
| October | 35.6°C21 Oct 1965 | 0.0°C30 Oct 1971 | 61 mm31 Oct 1927 | 96 mm1927 · driest 0 mm in 1949 | 100 |
| November | 34.4°C3 Nov 1950 | 1.1°C17 Nov 1958 | 79 mm20 Nov 1963 | 163 mm1944 · driest 0 mm in 1977 | 102 |
| December | 30.0°C11 Dec 1924 | 0.0°C30 Dec 1971 | 152 mm6 Dec 1997 | 174 mm1997 · driest 0 mm in 1999 | 102 |
| Month | Days 25°C+ | Days 30°C+ | Heavy rain (10 mm+) |
|---|---|---|---|
| January | 1 | 0 | 2 |
| February | <1 | 0 | 2 |
| March | <1 | 0 | 1 |
| April | <1 | <1 | <1 |
| May | <1 | <1 | <1 |
| June | <1 | <1 | <1 |
| July | 3 | <1 | 0 |
| August | 5 | <1 | 0 |
| September | 5 | <1 | <1 |
| October | 5 | <1 | <1 |
| November | 2 | <1 | <1 |
| December | 1 | 0 | <1 |
| Month | Warm & dry days | Wet days | Washouts | Week with 3+ wet days | Daytime mean has ranged |
|---|---|---|---|---|---|
| January | 19% | 17% | 6% | 18% | 15.6–19.5°C |
| February | 18% | 17% | 7% | 18% | 15.7–19.3°C |
| March | 18% | 14% | 4% | 12% | 16.2–19.8°C |
| April | 22% | 9% | 3% | 5% | 16.9–19.8°C |
| May | 34% | 3% | <1% | 1% | 17.9–21.3°C |
| June | 66% | 1% | <1% | 0% | 18.9–22.2°C |
| July | 93% | <1% | 0% | 0% | 20.7–24.1°C |
| August | 97% | <1% | <1% | <1% | 21.3–24.7°C |
| September | 94% | 2% | <1% | <1% | 21.1–25.0°C |
| October | 74% | 4% | <1% | 2% | 19.9–23.8°C |
| November | 45% | 9% | 3% | 6% | 18.4–21.8°C |
| December | 21% | 14% | 5% | 14% | 16.4–19.8°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 5339840
- NOAA station
- USC00046175 · NEWPORT BEACH HARBOR
- Station distance
- 5.3 km from the place centre
- Climate period
- 1991–2020
- Minimum month coverage
- 26 usable years
- Daylight
- Calculated from latitude 33.64°, mid-month, sunrise to sunset including refraction. Not a station measurement.
- Sea temperature
- NOAA OISST v2.1 1991–2020 monthly climatology, nearest open water 4 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.