Monthly outlook for Hercules, CA: average high 75.9°, average low 59°. That is 1.1° above the climate normal for October. Precipitation is expected on 0 days (about 0.0 inches), against a normal of 2 days and 0.6 inches. The warmest day looks like 16 October (85°), the coolest 11 October (47.6°).
75.9°/59°
Average high / low
+1.1°
Above normal
0 / 2
Wet days / normal
0.0 in
Precipitation this month
Ten-day blocks vs climate normal
Period
Forecast high
Normal
Difference
10 October – 19 October
74.4°
74.8°
-0.2°
20 October – 29 October
78.3°
71.2°
+4°
30 October – 8 November
at normal
67.9°
—
October records over 66 years
99.3°3 October 1980All-time high
39.6°29 October 1972All-time low
Climate normals and records are computed from the nearest reference point — Tara Hills (3 mi).
Sun, 1169° / 48°0
69 °
Hercules, Sunday, 11 October
Clear. High 69°, low 48°.
Pressure29.56 inHg
Wind8.9 mph S
Humidity58%
Visibility6.2 mi
Dew point50°
Mon, 1268° / 55°0
68 °
Hercules, Monday, 12 October
Clear. High 68°, low 55°.
Pressure29.88 inHg
Wind3.8 mph W
Humidity53%
Visibility6.2 mi
Dew point46°
Tue, 1373° / 53°0
73 °
Hercules, Tuesday, 13 October
Partly cloudy. High 73°, low 53°.
Pressure30.03 inHg
Wind3.6 mph SW
Humidity60%
Visibility2.5 mi
Dew point48°
Wed, 1471° / 56°0
71 °
Hercules, Wednesday, 14 October
Partly cloudy. High 71°, low 56°.
Pressure30.12 inHg
Wind7.8 mph SW
Humidity72%
Visibility—
Dew point53°
Thu, 1578° / 55°0
78 °
Hercules, Thursday, 15 October
Overcast. High 78°, low 55°.
Pressure30.12 inHg
Wind4.9 mph NW
Humidity76%
Visibility—
Dew point54°
Fri, 1685° / 64°0
85 °
Hercules, Friday, 16 October
Clear. High 85°, low 64°.
Pressure30.09 inHg
Wind5.6 mph NE
Humidity22%
Visibility—
Dew point32°
Sat, 1785° / 67°0
85 °
Hercules, Saturday, 17 October
Mostly clear. High 85°, low 67°.
Pressure30.03 inHg
Wind4.7 mph SW
Humidity24%
Visibility—
Dew point36°
Sun, 1875° / 62°0
75 °
Hercules, Sunday, 18 October
Overcast. High 75°, low 62°.
Pressure30.00 inHg
Wind7.1 mph SW
Humidity48%
Visibility—
Dew point49°
Mon, 1972° / 60°0
72 °
Hercules, Monday, 19 October
Mostly clear. High 72°, low 60°.
Pressure30.03 inHg
Wind7.8 mph S
Humidity53%
Visibility—
Dew point48°
Tue, 2079° / 60°0
79 °
Hercules, Tuesday, 20 October
Clear. High 79°, low 60°.
Pressure30.00 inHg
Wind6.6 mph SW
Humidity37%
Visibility—
Dew point42°
Wed, 2183° / 65°0
83 °
Hercules, Wednesday, 21 October
Mostly clear. High 83°, low 65°.
Pressure29.97 inHg
Wind5.5 mph NE
Humidity21%
Visibility—
Dew point30°
Thu, 2280° / 64°0
80 °
Hercules, Thursday, 22 October
Partly cloudy. High 80°, low 64°.
Pressure29.88 inHg
Wind10.5 mph SW
Humidity25%
Visibility—
Dew point35°
Fri, 2368° / 60°0
68 °
Hercules, Friday, 23 October
Overcast. High 68°, low 60°.
Pressure29.97 inHg
Wind10.3 mph SW
Humidity74%
Visibility—
Dew point56°
Sat, 2476° / 59°0
76 °
Hercules, Saturday, 24 October
Clear. High 76°, low 59°.
Pressure30.06 inHg
Wind4.6 mph SW
Humidity48%
Visibility—
Dew point47°
Sun, 2584° / 64°0
84 °
Hercules, Sunday, 25 October
Partly cloudy. High 84°, low 64°.
Pressure30.06 inHg
Wind5.4 mph NE
Humidity24%
Visibility—
Dew point33°
From day 17 onward the outlook is built from 60-year climate statistics
Mon, 2671° / 51°0.05
71 °
Hercules, Monday, 26 October
Climate normal for this date — 60-year average.
Average high71°
Average low51°
Average precipitation0.05 in
Chance of precipitation10%
Record high89° (2003)
Record low43° (1970)
Tue, 2770° / 50°0.02
70 °
Hercules, Tuesday, 27 October
Climate normal for this date — 60-year average.
Average high70°
Average low50°
Average precipitation0.02 in
Chance of precipitation7%
Record high88° (2003)
Record low41° (2010)
Wed, 2869° / 50°0.07
69 °
Hercules, Wednesday, 28 October
Climate normal for this date — 60-year average.
Average high69°
Average low50°
Average precipitation0.07 in
Chance of precipitation17%
Record high87° (2003)
Record low42° (1970)
Thu, 2969° / 50°0.06
69 °
Hercules, Thursday, 29 October
Climate normal for this date — 60-year average.
Average high69°
Average low50°
Average precipitation0.06 in
Chance of precipitation22%
Record high83° (1965)
Record low40° (1972)
Fri, 3068° / 50°0.06
68 °
Hercules, Friday, 30 October
Climate normal for this date — 60-year average.
Average high68°
Average low50°
Average precipitation0.06 in
Chance of precipitation17%
Record high83° (1966)
Record low40° (1971)
Sat, 3169° / 49°0.02
69 °
Hercules, Saturday, 31 October
Climate normal for this date — 60-year average.
Average high69°
Average low49°
Average precipitation0.02 in
Chance of precipitation12%
Record high84° (1966)
Record low42° (1989)
Sun, 0169° / 49°0.05
69 °
Hercules, Sunday, 1 November
Climate normal for this date — 60-year average.
Average high69°
Average low49°
Average precipitation0.05 in
Chance of precipitation15%
Record high85° (1967)
Record low39° (2003)
Mon, 0269° / 49°0.03
69 °
Hercules, Monday, 2 November
Climate normal for this date — 60-year average.
Average high69°
Average low49°
Average precipitation0.03 in
Chance of precipitation12%
Record high86° (1967)
Record low40° (2003)
Tue, 0369° / 49°0.03
69 °
Hercules, Tuesday, 3 November
Climate normal for this date — 60-year average.
Average high69°
Average low49°
Average precipitation0.03 in
Chance of precipitation12%
Record high82° (1976)
Record low40° (1971)
Wed, 0468° / 49°0.02
68 °
Hercules, Wednesday, 4 November
Climate normal for this date — 60-year average.
Average high68°
Average low49°
Average precipitation0.02 in
Chance of precipitation10%
Record high81° (1976)
Record low39° (1973)
Thu, 0567° / 49°0.05
67 °
Hercules, Thursday, 5 November
Climate normal for this date — 60-year average.
Average high67°
Average low49°
Average precipitation0.05 in
Chance of precipitation15%
Record high82° (1976)
Record low40° (1996)
Fri, 0667° / 50°0.06
67 °
Hercules, Friday, 6 November
Climate normal for this date — 60-year average.
Average high67°
Average low50°
Average precipitation0.06 in
Chance of precipitation18%
Record high81° (1976)
Record low41° (1996)
Sat, 0767° / 49°0.07
67 °
Hercules, Saturday, 7 November
Climate normal for this date — 60-year average.
Average high67°
Average low49°
Average precipitation0.07 in
Chance of precipitation23%
Record high80° (1991)
Record low39° (1971)
Sun, 0865° / 48°0.07
65 °
Hercules, Sunday, 8 November
Climate normal for this date — 60-year average.
Average high65°
Average low48°
Average precipitation0.07 in
Chance of precipitation22%
Record high79° (1978)
Record low41° (1994)
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 Hercules, 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 Hercules, 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.