As of 20:49 PDT

Weather in Diamond Bar, CA

73°Current weather

Diamond Bar, Sunday, 18 October, 20:49

Clear. Feels like 72°. High 85°, low 63°.

Pressure29.94 inHg
Wind4.6 mph W
Humidity47%
Visibility6.2 mi
Dew point51°

Monthly outlook for Diamond Bar, CA: average high 77.9°, average low 63.2°. That is 0.5° above the climate normal for October. Precipitation is expected on 3 days (about 0.8 inches), against a normal of 2 days and 0.4 inches. The warmest day looks like 25 October (88.6°), the coolest 24 October (55.7°).

77.9°/63.2°
Average high / low
+0.5°
Above normal
3 / 2
Wet days / normal
0.8 in
Precipitation this month

Ten-day blocks vs climate normal

PeriodForecast highNormalDifference
18 October – 27 October81.1°78.2°+1.6°
28 October – 6 November72.6°75°-1.4°
7 November – 16 Novemberat normal71.5°—

October records over 66 years

104°1 October 2020All-time high
34.2°29 October 1971All-time low

Climate normals and records are computed from the nearest reference point — Pomona (5 mi).

Mon, 1984° / 65°0Clear
84 °Clear

Diamond Bar, Monday, 19 October

Clear. High 84°, low 65°.

Pressure29.91 inHg
Wind1.9 mph SW
Humidity21%
Visibility6.2 mi
Dew point42°
Tue, 2087° / 64°0Clear
87 °Clear

Diamond Bar, Tuesday, 20 October

Clear. High 87°, low 64°.

Pressure29.85 inHg
Wind1.9 mph SW
Humidity31%
Visibility6.2 mi
Dew point50°
Wed, 2181° / 63°0.06Light rain
81 °Light rain

Diamond Bar, Wednesday, 21 October

Light rain. High 81°, low 63°.

Pressure29.91 inHg
Wind2.2 mph S
Humidity43%
Visibility6.2 mi
Dew point54°
Thu, 2267° / 61°0.69Rain
67 °Rain

Diamond Bar, Thursday, 22 October

Rain. High 67°, low 61°.

Pressure29.94 inHg
Wind1.7 mph SE
Humidity76%
Visibility4.6 mi
Dew point57°
Fri, 2372° / 58°0Clear
72 °Clear

Diamond Bar, Friday, 23 October

Clear. High 72°, low 58°.

Pressure30.03 inHg
Wind4.3 mph SW
Humidity68%
Visibility—
Dew point55°
Sat, 2482° / 56°0Clear
82 °Clear

Diamond Bar, Saturday, 24 October

Clear. High 82°, low 56°.

Pressure30.03 inHg
Wind5.2 mph W
Humidity50%
Visibility—
Dew point50°
Sun, 2589° / 72°0Clear
89 °Clear

Diamond Bar, Sunday, 25 October

Clear. High 89°, low 72°.

Pressure29.91 inHg
Wind6.9 mph W
Humidity11%
Visibility—
Dew point22°
Mon, 2686° / 73°0Clear
86 °Clear

Diamond Bar, Monday, 26 October

Clear. High 86°, low 73°.

Pressure29.80 inHg
Wind7.9 mph SW
Humidity13%
Visibility—
Dew point25°
Tue, 2778° / 66°0Partly cloudy
78 °Partly cloudy

Diamond Bar, Tuesday, 27 October

Partly cloudy. High 78°, low 66°.

Pressure29.85 inHg
Wind10.1 mph SW
Humidity50%
Visibility—
Dew point53°
Wed, 2866° / 62°0.08Light rain
66 °Light rain

Diamond Bar, Wednesday, 28 October

Light rain. High 66°, low 62°.

Pressure29.91 inHg
Wind12.9 mph SW
Humidity69%
Visibility—
Dew point55°
Thu, 2969° / 59°0Clear
69 °Clear

Diamond Bar, Thursday, 29 October

Clear. High 69°, low 59°.

Pressure30.00 inHg
Wind11.2 mph SW
Humidity30%
Visibility—
Dew point32°
Fri, 3071° / 60°0Clear
71 °Clear

Diamond Bar, Friday, 30 October

Clear. High 71°, low 60°.

Pressure29.97 inHg
Wind7 mph SW
Humidity39%
Visibility—
Dew point39°
Sat, 3177° / 63°0Clear
77 °Clear

Diamond Bar, Saturday, 31 October

Clear. High 77°, low 63°.

Pressure30.12 inHg
Wind7.8 mph E
Humidity8%
Visibility—
Dew point6°
Sun, 0178° / 64°0Clear
78 °Clear

Diamond Bar, Sunday, 1 November

Clear. High 78°, low 64°.

Pressure30.09 inHg
Wind6.9 mph W
Humidity8%
Visibility—
Dew point7°
Mon, 0274° / 64°0Clear
74 °Clear

Diamond Bar, Monday, 2 November

Clear. High 74°, low 64°.

Pressure29.94 inHg
Wind9.6 mph SW
Humidity31%
Visibility—
Dew point37°
From day 17 onward the outlook is built from 60-year climate statistics
Tue, 0376° / 52°0Climate normal
76 °Climate normal

Diamond Bar, Tuesday, 3 November

Climate normal for this date — 60-year average.

Average high76°
Average low52°
Average precipitation0 in
Chance of precipitation5%
Record high91° (1976)
Record low42° (1974)
Wed, 0476° / 53°0.03Climate normal
76 °Climate normal

Diamond Bar, Wednesday, 4 November

Climate normal for this date — 60-year average.

Average high76°
Average low53°
Average precipitation0.03 in
Chance of precipitation5%
Record high91° (1976)
Record low39° (1994)
Thu, 0574° / 51°0.01Climate normal
74 °Climate normal

Diamond Bar, Thursday, 5 November

Climate normal for this date — 60-year average.

Average high74°
Average low51°
Average precipitation0.01 in
Chance of precipitation5%
Record high95° (2020)
Record low39° (2011)
Fri, 0673° / 52°0.02Climate normal
73 °Climate normal

Diamond Bar, Friday, 6 November

Climate normal for this date — 60-year average.

Average high73°
Average low52°
Average precipitation0.02 in
Chance of precipitation8%
Record high90° (2006)
Record low40° (2011)
Sat, 0772° / 51°0.06Climate normal
72 °Climate normal

Diamond Bar, Saturday, 7 November

Climate normal for this date — 60-year average.

Average high72°
Average low51°
Average precipitation0.06 in
Chance of precipitation12%
Record high91° (2006)
Record low37° (2011)
Sun, 0872° / 51°0.09Climate normal
72 °Climate normal

Diamond Bar, Sunday, 8 November

Climate normal for this date — 60-year average.

Average high72°
Average low51°
Average precipitation0.09 in
Chance of precipitation22%
Record high90° (2016)
Record low39° (2011)
Mon, 0972° / 51°0.05Climate normal
72 °Climate normal

Diamond Bar, Monday, 9 November

Climate normal for this date — 60-year average.

Average high72°
Average low51°
Average precipitation0.05 in
Chance of precipitation12%
Record high91° (2016)
Record low40° (2020)
Tue, 1071° / 50°0.04Climate normal
71 °Climate normal

Diamond Bar, Tuesday, 10 November

Climate normal for this date — 60-year average.

Average high71°
Average low50°
Average precipitation0.04 in
Chance of precipitation10%
Record high90° (2025)
Record low42° (1966)
Wed, 1171° / 50°0.06Climate normal
71 °Climate normal

Diamond Bar, Wednesday, 11 November

Climate normal for this date — 60-year average.

Average high71°
Average low50°
Average precipitation0.06 in
Chance of precipitation13%
Record high90° (2021)
Record low37° (1982)
Thu, 1272° / 50°0.04Climate normal
72 °Climate normal

Diamond Bar, Thursday, 12 November

Climate normal for this date — 60-year average.

Average high72°
Average low50°
Average precipitation0.04 in
Chance of precipitation13%
Record high92° (2021)
Record low34° (1978)
Fri, 1372° / 50°0.04Climate normal
72 °Climate normal

Diamond Bar, Friday, 13 November

Climate normal for this date — 60-year average.

Average high72°
Average low50°
Average precipitation0.04 in
Chance of precipitation10%
Record high91° (2021)
Record low34° (1985)
Sat, 1472° / 50°0.04Climate normal
72 °Climate normal

Diamond Bar, Saturday, 14 November

Climate normal for this date — 60-year average.

Average high72°
Average low50°
Average precipitation0.04 in
Chance of precipitation7%
Record high91° (2021)
Record low35° (2000)
Sun, 1571° / 49°0.07Climate normal
71 °Climate normal

Diamond Bar, Sunday, 15 November

Climate normal for this date — 60-year average.

Average high71°
Average low49°
Average precipitation0.07 in
Chance of precipitation10%
Record high86° (2021)
Record low35° (1964)
Mon, 1670° / 49°0.05Climate normal
70 °Climate normal

Diamond Bar, Monday, 16 November

Climate normal for this date — 60-year average.

Average high70°
Average low49°
Average precipitation0.05 in
Chance of precipitation10%
Record high90° (2020)
Record low34° (1964)

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 Diamond Bar, 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 Diamond Bar, 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.