Monthly outlook for Costa Mesa, CA: average high 72.7°, average low 62.6°. That is 0.4° above the climate normal for October. Precipitation is expected on 4 days (about 2.0 inches), against a normal of 1 days and 0.3 inches. The warmest day looks like 26 October (80.7°), the coolest 25 October (57.3°).
72.7°/62.6°
Average high / low
+0.4°
Above normal
4 / 1
Wet days / normal
2.0 in
Precipitation this month
Ten-day blocks vs climate normal
Period
Forecast high
Normal
Difference
23 October – 1 November
74.4°
72.6°
+1°
2 November – 11 November
69.9°
70.2°
-0.1°
12 November – 21 November
at normal
68.3°
—
October records over 66 years
99.7°24 October 2017All-time high
39.9°30 October 1971All-time low
Sat, 2481° / 59°0
81 °
Costa Mesa, Saturday, 24 October
Clear. High 81°, low 59°.
Pressure29.97 inHg
Wind1.8 mph W
Humidity57%
Visibility6.2 mi
Dew point55°
Sun, 2579° / 57°0
79 °
Costa Mesa, Sunday, 25 October
Clear. High 79°, low 57°.
Pressure30.03 inHg
Wind3.2 mph SW
Humidity47%
Visibility6.2 mi
Dew point55°
Mon, 2681° / 58°0
81 °
Costa Mesa, Monday, 26 October
Overcast. High 81°, low 58°.
Pressure30.03 inHg
Wind2.2 mph SW
Humidity39%
Visibility6.2 mi
Dew point51°
Tue, 2776° / 59°0
76 °
Costa Mesa, Tuesday, 27 October
Mostly clear. High 76°, low 59°.
Pressure29.97 inHg
Wind5.7 mph SW
Humidity68%
Visibility—
Dew point60°
Wed, 2876° / 59°0
76 °
Costa Mesa, Wednesday, 28 October
Overcast. High 76°, low 59°.
Pressure29.94 inHg
Wind5.6 mph SW
Humidity66%
Visibility—
Dew point58°
Thu, 2970° / 66°0
70 °
Costa Mesa, Thursday, 29 October
Overcast. High 70°, low 66°.
Pressure29.94 inHg
Wind8.1 mph SW
Humidity57%
Visibility—
Dew point52°
Fri, 3070° / 66°0
70 °
Costa Mesa, Friday, 30 October
Overcast. High 70°, low 66°.
Pressure29.94 inHg
Wind9.5 mph SW
Humidity60%
Visibility—
Dew point54°
Sat, 3168° / 65°0.37
68 °
Costa Mesa, Saturday, 31 October
Rain. High 68°, low 65°.
Pressure29.83 inHg
Wind18.6 mph SE
Humidity65%
Visibility—
Dew point55°
Sun, 0169° / 65°1.28
69 °
Costa Mesa, Sunday, 1 November
Rain. High 69°, low 65°.
Pressure29.68 inHg
Wind19.4 mph S
Humidity72%
Visibility—
Dew point59°
Mon, 0267° / 65°0.32
67 °
Costa Mesa, Monday, 2 November
Light rain. High 67°, low 65°.
Pressure29.97 inHg
Wind13.1 mph W
Humidity59%
Visibility—
Dew point52°
Tue, 0367° / 64°0.01
67 °
Costa Mesa, Tuesday, 3 November
Light rain. High 67°, low 64°.
Pressure30.03 inHg
Wind8.8 mph SW
Humidity59%
Visibility—
Dew point51°
Wed, 0467° / 63°0
67 °
Costa Mesa, Wednesday, 4 November
Overcast. High 67°, low 63°.
Pressure30.00 inHg
Wind7.2 mph SW
Humidity64%
Visibility—
Dew point53°
Thu, 0568° / 63°0
68 °
Costa Mesa, Thursday, 5 November
Partly cloudy. High 68°, low 63°.
Pressure30.12 inHg
Wind7 mph SW
Humidity61%
Visibility—
Dew point52°
Fri, 0676° / 65°0
76 °
Costa Mesa, Friday, 6 November
Mostly clear. High 76°, low 65°.
Pressure30.12 inHg
Wind8.1 mph W
Humidity37%
Visibility—
Dew point43°
Sat, 0774° / 68°0
74 °
Costa Mesa, Saturday, 7 November
Overcast. High 74°, low 68°.
Pressure30.06 inHg
Wind7.4 mph SW
Humidity46%
Visibility—
Dew point49°
From day 17 onward the outlook is built from 60-year climate statistics
Sun, 0869° / 54°0.07
69 °
Costa Mesa, Sunday, 8 November
Climate normal for this date — 60-year average.
Average high69°
Average low54°
Average precipitation0.07 in
Chance of precipitation18%
Record high83° (1976)
Record low45° (2011)
Mon, 0969° / 55°0.04
69 °
Costa Mesa, Monday, 9 November
Climate normal for this date — 60-year average.
Average high69°
Average low55°
Average precipitation0.04 in
Chance of precipitation12%
Record high89° (2016)
Record low46° (2011)
Tue, 1069° / 54°0.03
69 °
Costa Mesa, Tuesday, 10 November
Climate normal for this date — 60-year average.
Average high69°
Average low54°
Average precipitation0.03 in
Chance of precipitation8%
Record high86° (1990)
Record low45° (2020)
Wed, 1169° / 53°0.04
69 °
Costa Mesa, Wednesday, 11 November
Climate normal for this date — 60-year average.
Average high69°
Average low53°
Average precipitation0.04 in
Chance of precipitation10%
Record high86° (2021)
Record low44° (2012)
Thu, 1270° / 53°0.04
70 °
Costa Mesa, Thursday, 12 November
Climate normal for this date — 60-year average.
Average high70°
Average low53°
Average precipitation0.04 in
Chance of precipitation15%
Record high92° (2021)
Record low43° (1978)
Fri, 1370° / 53°0.03
70 °
Costa Mesa, Friday, 13 November
Climate normal for this date — 60-year average.
Average high70°
Average low53°
Average precipitation0.03 in
Chance of precipitation12%
Record high84° (2013)
Record low42° (2000)
Sat, 1469° / 53°0.04
69 °
Costa Mesa, Saturday, 14 November
Climate normal for this date — 60-year average.
Average high69°
Average low53°
Average precipitation0.04 in
Chance of precipitation8%
Record high84° (2008)
Record low41° (1985)
Sun, 1569° / 53°0.06
69 °
Costa Mesa, Sunday, 15 November
Climate normal for this date — 60-year average.
Average high69°
Average low53°
Average precipitation0.06 in
Chance of precipitation7%
Record high85° (2008)
Record low43° (1964)
Mon, 1668° / 53°0.05
68 °
Costa Mesa, Monday, 16 November
Climate normal for this date — 60-year average.
Average high68°
Average low53°
Average precipitation0.05 in
Chance of precipitation7%
Record high83° (2008)
Record low40° (1964)
Tue, 1768° / 53°0.04
68 °
Costa Mesa, Tuesday, 17 November
Climate normal for this date — 60-year average.
Average high68°
Average low53°
Average precipitation0.04 in
Chance of precipitation12%
Record high90° (2019)
Record low42° (1971)
Wed, 1867° / 52°0.04
67 °
Costa Mesa, Wednesday, 18 November
Climate normal for this date — 60-year average.
Average high67°
Average low52°
Average precipitation0.04 in
Chance of precipitation10%
Record high82° (1989)
Record low40° (1964)
Thu, 1968° / 51°0.06
68 °
Costa Mesa, Thursday, 19 November
Climate normal for this date — 60-year average.
Average high68°
Average low51°
Average precipitation0.06 in
Chance of precipitation5%
Record high84° (1989)
Record low38° (1994)
Fri, 2068° / 52°0.07
68 °
Costa Mesa, Friday, 20 November
Climate normal for this date — 60-year average.
Average high68°
Average low52°
Average precipitation0.07 in
Chance of precipitation13%
Record high81° (2002)
Record low39° (1964)
Sat, 2167° / 51°0.06
67 °
Costa Mesa, Saturday, 21 November
Climate normal for this date — 60-year average.
Average high67°
Average low51°
Average precipitation0.06 in
Chance of precipitation17%
Record high85° (2021)
Record low40° (1979)
About the monthly outlook
How accurate is a 30-day forecast?
The first 16 days come from weather models — reliable for the first 3–5 days and progressively less so after that. Days 17 through 30 for Costa Mesa, CA are built from the climate normal, the 60-year average, so they show typical weather for those dates rather than a specific forecast.
What does "above normal" mean?
We compare the forecast against the climate normal for those exact calendar days, computed from 60 years of observations. The deviation shows how much the coming month differs from a typical one.
Where do the 66-year records come from?
They are real temperature extremes recorded in Costa Mesa, CA since 1960: the highest and lowest reading for each calendar date, with the year it happened.
How often is it updated?
The forecast portion refreshes every hour; the climate portion is based on long-term data and stays stable.