Monthly outlook for Walnut, CA: average high 81.4°, average low 65.9°. That is 0.9° above the climate normal for October. Precipitation is expected on 2 days (about 0.8 inches), against a normal of 1 days and 0.3 inches. The warmest day looks like 8 October (95.5°), the coolest 13 October (54.3°).
81.4°/65.9°
Average high / low
+0.9°
Above normal
2 / 1
Wet days / normal
0.8 in
Precipitation this month
Ten-day blocks vs climate normal
Period
Forecast high
Normal
Difference
8 October – 17 October
80°
80.4°
-0.2°
18 October – 27 October
83.6°
78.3°
+2.9°
28 October – 6 November
at normal
75.5°
—
October records over 66 years
105.4°1 October 2020All-time high
34.2°29 October 1971All-time low
Climate normals and records are computed from the nearest reference point — South San Jose Hills (3 mi).
Fri, 0990° / 65°0
90 °
Walnut, Friday, 9 October
Clear. High 90°, low 65°.
Pressure29.80 inHg
Wind3.5 mph SW
Humidity35%
Visibility6.2 mi
Dew point57°
Sat, 1080° / 67°0
80 °
Walnut, Saturday, 10 October
Overcast. High 80°, low 67°.
Pressure29.71 inHg
Wind1.4 mph SW
Humidity56%
Visibility6.2 mi
Dew point59°
Sun, 1181° / 64°0.02
81 °
Walnut, Sunday, 11 October
Light rain. High 81°, low 64°.
Pressure29.50 inHg
Wind5.1 mph SW
Humidity35%
Visibility6.2 mi
Dew point49°
Mon, 1266° / 58°0.62
66 °
Walnut, Monday, 12 October
Rain. High 66°, low 58°.
Pressure29.85 inHg
Wind4.5 mph W
Humidity72%
Visibility—
Dew point54°
Tue, 1370° / 54°0.19
70 °
Walnut, Tuesday, 13 October
Light rain. High 70°, low 54°.
Pressure29.91 inHg
Wind7.9 mph SW
Humidity59%
Visibility—
Dew point49°
Wed, 1470° / 61°0
70 °
Walnut, Wednesday, 14 October
Mostly clear. High 70°, low 61°.
Pressure29.91 inHg
Wind11.5 mph S
Humidity56%
Visibility—
Dew point50°
Thu, 1577° / 64°0
77 °
Walnut, Thursday, 15 October
Partly cloudy. High 77°, low 64°.
Pressure30.00 inHg
Wind8.7 mph SW
Humidity46%
Visibility—
Dew point48°
Fri, 1685° / 66°0
85 °
Walnut, Friday, 16 October
Clear. High 85°, low 66°.
Pressure30.09 inHg
Wind4 mph NE
Humidity11%
Visibility—
Dew point18°
Sat, 1786° / 68°0
86 °
Walnut, Saturday, 17 October
Clear. High 86°, low 68°.
Pressure29.97 inHg
Wind4.3 mph NE
Humidity9%
Visibility—
Dew point15°
Sun, 1888° / 70°0
88 °
Walnut, Sunday, 18 October
Mostly clear. High 88°, low 70°.
Pressure29.91 inHg
Wind6.9 mph SW
Humidity7%
Visibility—
Dew point10°
Mon, 1984° / 72°0
84 °
Walnut, Monday, 19 October
Overcast. High 84°, low 72°.
Pressure29.94 inHg
Wind6.3 mph W
Humidity9%
Visibility—
Dew point15°
Tue, 2088° / 71°0
88 °
Walnut, Tuesday, 20 October
Clear. High 88°, low 71°.
Pressure29.88 inHg
Wind8.2 mph W
Humidity8%
Visibility—
Dew point13°
Wed, 2188° / 72°0
88 °
Walnut, Wednesday, 21 October
Mostly clear. High 88°, low 72°.
Pressure29.94 inHg
Wind8 mph SW
Humidity12%
Visibility—
Dew point24°
Thu, 2281° / 67°0
81 °
Walnut, Thursday, 22 October
Clear. High 81°, low 67°.
Pressure29.85 inHg
Wind9.7 mph SW
Humidity37%
Visibility—
Dew point47°
Fri, 2373° / 65°0
73 °
Walnut, Friday, 23 October
Clear. High 73°, low 65°.
Pressure29.88 inHg
Wind4.6 mph SW
Humidity49%
Visibility—
Dew point52°
From day 17 onward the outlook is built from 60-year climate statistics
Sat, 2479° / 56°0
79 °
Walnut, Saturday, 24 October
Climate normal for this date — 60-year average.
Average high79°
Average low56°
Average precipitation0 in
Chance of precipitation3%
Record high103° (2017)
Record low47° (1975)
Sun, 2578° / 56°0.02
78 °
Walnut, Sunday, 25 October
Climate normal for this date — 60-year average.
Average high78°
Average low56°
Average precipitation0.02 in
Chance of precipitation5%
Record high100° (2017)
Record low42° (1971)
Mon, 2678° / 55°0.01
78 °
Walnut, Monday, 26 October
Climate normal for this date — 60-year average.
Average high78°
Average low55°
Average precipitation0.01 in
Chance of precipitation3%
Record high92° (2017)
Record low44° (1989)
Tue, 2777° / 54°0.05
77 °
Walnut, Tuesday, 27 October
Climate normal for this date — 60-year average.
Average high77°
Average low54°
Average precipitation0.05 in
Chance of precipitation10%
Record high93° (1965)
Record low43° (1996)
Wed, 2876° / 53°0.02
76 °
Walnut, Wednesday, 28 October
Climate normal for this date — 60-year average.
Average high76°
Average low53°
Average precipitation0.02 in
Chance of precipitation13%
Record high93° (2008)
Record low44° (1996)
Thu, 2975° / 53°0
75 °
Walnut, Thursday, 29 October
Climate normal for this date — 60-year average.
Average high75°
Average low53°
Average precipitation0 in
Chance of precipitation2%
Record high91° (1965)
Record low34° (1971)
Fri, 3075° / 52°0.05
75 °
Walnut, Friday, 30 October
Climate normal for this date — 60-year average.
Average high75°
Average low52°
Average precipitation0.05 in
Chance of precipitation15%
Record high92° (1966)
Record low34° (1971)
Sat, 3175° / 52°0.02
75 °
Walnut, Saturday, 31 October
Climate normal for this date — 60-year average.
Average high75°
Average low52°
Average precipitation0.02 in
Chance of precipitation5%
Record high91° (1966)
Record low38° (1971)
Sun, 0176° / 52°0.03
76 °
Walnut, Sunday, 1 November
Climate normal for this date — 60-year average.
Average high76°
Average low52°
Average precipitation0.03 in
Chance of precipitation12%
Record high94° (1997)
Record low41° (1971)
Mon, 0276° / 52°0.02
76 °
Walnut, Monday, 2 November
Climate normal for this date — 60-year average.
Average high76°
Average low52°
Average precipitation0.02 in
Chance of precipitation15%
Record high94° (1997)
Record low44° (1971)
Tue, 0377° / 51°0
77 °
Walnut, Tuesday, 3 November
Climate normal for this date — 60-year average.
Average high77°
Average low51°
Average precipitation0 in
Chance of precipitation3%
Record high93° (2010)
Record low41° (1990)
Wed, 0476° / 52°0.02
76 °
Walnut, Wednesday, 4 November
Climate normal for this date — 60-year average.
Average high76°
Average low52°
Average precipitation0.02 in
Chance of precipitation5%
Record high93° (1976)
Record low38° (1994)
Thu, 0574° / 51°0.01
74 °
Walnut, Thursday, 5 November
Climate normal for this date — 60-year average.
Average high74°
Average low51°
Average precipitation0.01 in
Chance of precipitation3%
Record high97° (2020)
Record low40° (2011)
Fri, 0674° / 52°0.02
74 °
Walnut, Friday, 6 November
Climate normal for this date — 60-year average.
Average high74°
Average low52°
Average precipitation0.02 in
Chance of precipitation8%
Record high91° (2006)
Record low41° (2011)
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 Walnut, 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 Walnut, 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.