Monthly outlook for Crestline, CA: average high 89.3°, average low 64°. That is 1.1° below the climate normal for August. Precipitation is expected on 1 day (about 0.0 inches), against a normal of 2 days and 0.4 inches. The warmest day looks like 19 August (92.9°), the coolest 13 August (58.2°).
89.3°/64°
Average high / low
−1.1°
Below normal
1 / 2
Wet days / normal
0.0 in
Precipitation this month
Ten-day blocks vs climate normal
Period
Forecast high
Normal
Difference
8 August – 17 August
87.9°
91.9°
-2.2°
18 August – 27 August
91.7°
91°
+0.4°
28 August – 6 September
at normal
92.8°
—
August records over 66 years
111.7°18 August 2020All-time high
49.5°22 August 1968All-time low
Climate normals and records are computed from the nearest reference point — San Bernardino (7 mi).
Sun, 0991° / 67°0
91 °
Crestline, Sunday, 9 August
Clear. High 91°, low 67°.
Pressure29.85 inHg
Wind11.4 mph S
Humidity16%
Visibility6.2 mi
Dew point42°
Mon, 1092° / 67°0
92 °
Crestline, Monday, 10 August
Partly cloudy. High 92°, low 67°.
Pressure29.91 inHg
Wind10.7 mph S
Humidity19%
Visibility6.2 mi
Dew point44°
Tue, 1188° / 63°0
88 °
Crestline, Tuesday, 11 August
Overcast. High 88°, low 63°.
Pressure29.97 inHg
Wind9.1 mph S
Humidity22%
Visibility6.2 mi
Dew point44°
Wed, 1285° / 62°0
85 °
Crestline, Wednesday, 12 August
Partly cloudy. High 85°, low 62°.
Pressure29.88 inHg
Wind10.1 mph S
Humidity24%
Visibility6.2 mi
Dew point44°
Thu, 1381° / 58°0
81 °
Crestline, Thursday, 13 August
Partly cloudy. High 81°, low 58°.
Pressure29.94 inHg
Wind10.3 mph S
Humidity34%
Visibility—
Dew point40°
Fri, 1482° / 58°0
82 °
Crestline, Friday, 14 August
Overcast. High 82°, low 58°.
Pressure29.97 inHg
Wind11.8 mph S
Humidity29%
Visibility—
Dew point41°
Sat, 1588° / 60°0
88 °
Crestline, Saturday, 15 August
Clear. High 88°, low 60°.
Pressure30.00 inHg
Wind11.3 mph S
Humidity24%
Visibility—
Dew point40°
Sun, 1691° / 63°0
91 °
Crestline, Sunday, 16 August
Partly cloudy. High 91°, low 63°.
Pressure30.00 inHg
Wind11.2 mph S
Humidity20%
Visibility—
Dew point38°
Mon, 1790° / 64°0
90 °
Crestline, Monday, 17 August
Overcast. High 90°, low 64°.
Pressure30.06 inHg
Wind11.3 mph S
Humidity20%
Visibility—
Dew point38°
Tue, 1892° / 66°0
92 °
Crestline, Tuesday, 18 August
Clear. High 92°, low 66°.
Pressure29.97 inHg
Wind10.8 mph S
Humidity18%
Visibility—
Dew point38°
Wed, 1993° / 68°0
93 °
Crestline, Wednesday, 19 August
Clear. High 93°, low 68°.
Pressure29.91 inHg
Wind11.3 mph S
Humidity19%
Visibility—
Dew point39°
Thu, 2092° / 67°0
92 °
Crestline, Thursday, 20 August
Partly cloudy. High 92°, low 67°.
Pressure29.91 inHg
Wind10.9 mph S
Humidity21%
Visibility—
Dew point41°
Fri, 2191° / 67°0
91 °
Crestline, Friday, 21 August
Overcast. High 91°, low 67°.
Pressure29.88 inHg
Wind11.2 mph S
Humidity25%
Visibility—
Dew point46°
Sat, 2292° / 67°0.04
92 °
Crestline, Saturday, 22 August
Light rain. High 92°, low 67°.
Pressure29.88 inHg
Wind10.7 mph S
Humidity28%
Visibility—
Dew point49°
Sun, 2390° / 66°0
90 °
Crestline, Sunday, 23 August
Overcast. High 90°, low 66°.
Pressure29.88 inHg
Wind11.7 mph S
Humidity31%
Visibility—
Dew point50°
From day 17 onward the outlook is built from 60-year climate statistics
Mon, 2492° / 67°0.01
92 °
Crestline, Monday, 24 August
Climate normal for this date — 60-year average.
Average high92°
Average low67°
Average precipitation0.01 in
Chance of precipitation10%
Record high107° (2010)
Record low55° (1983)
Tue, 2592° / 68°0.02
92 °
Crestline, Tuesday, 25 August
Climate normal for this date — 60-year average.
Average high92°
Average low68°
Average precipitation0.02 in
Chance of precipitation10%
Record high104° (1985)
Record low56° (1990)
Wed, 2692° / 68°0.02
92 °
Crestline, Wednesday, 26 August
Climate normal for this date — 60-year average.
Average high92°
Average low68°
Average precipitation0.02 in
Chance of precipitation10%
Record high103° (2011)
Record low55° (1973)
Thu, 2793° / 67°0.01
93 °
Crestline, Thursday, 27 August
Climate normal for this date — 60-year average.
Average high93°
Average low67°
Average precipitation0.01 in
Chance of precipitation8%
Record high105° (2021)
Record low55° (1973)
Fri, 2894° / 67°0.01
94 °
Crestline, Friday, 28 August
Climate normal for this date — 60-year average.
Average high94°
Average low67°
Average precipitation0.01 in
Chance of precipitation3%
Record high107° (2017)
Record low55° (1973)
Sat, 2994° / 68°0.01
94 °
Crestline, Saturday, 29 August
Climate normal for this date — 60-year average.
Average high94°
Average low68°
Average precipitation0.01 in
Chance of precipitation10%
Record high107° (2017)
Record low55° (2010)
Sun, 3093° / 68°0.02
93 °
Crestline, Sunday, 30 August
Climate normal for this date — 60-year average.
Average high93°
Average low68°
Average precipitation0.02 in
Chance of precipitation12%
Record high108° (2017)
Record low55° (2010)
Mon, 3192° / 67°0.01
92 °
Crestline, Monday, 31 August
Climate normal for this date — 60-year average.
Average high92°
Average low67°
Average precipitation0.01 in
Chance of precipitation7%
Record high107° (2022)
Record low54° (1964)
Tue, 0192° / 66°0.02
92 °
Crestline, Tuesday, 1 September
Climate normal for this date — 60-year average.
Average high92°
Average low66°
Average precipitation0.02 in
Chance of precipitation10%
Record high107° (2017)
Record low54° (1964)
Wed, 0292° / 66°0.04
92 °
Crestline, Wednesday, 2 September
Climate normal for this date — 60-year average.
Average high92°
Average low66°
Average precipitation0.04 in
Chance of precipitation15%
Record high105° (2007)
Record low50° (1964)
Thu, 0392° / 67°0.02
92 °
Crestline, Thursday, 3 September
Climate normal for this date — 60-year average.
Average high92°
Average low67°
Average precipitation0.02 in
Chance of precipitation10%
Record high110° (2022)
Record low55° (1999)
Fri, 0492° / 67°0.01
92 °
Crestline, Friday, 4 September
Climate normal for this date — 60-year average.
Average high92°
Average low67°
Average precipitation0.01 in
Chance of precipitation8%
Record high109° (2022)
Record low54° (1985)
Sat, 0592° / 67°0.01
92 °
Crestline, Saturday, 5 September
Climate normal for this date — 60-year average.
Average high92°
Average low67°
Average precipitation0.01 in
Chance of precipitation7%
Record high113° (2020)
Record low56° (2016)
Sun, 0692° / 67°0.01
92 °
Crestline, Sunday, 6 September
Climate normal for this date — 60-year average.
Average high92°
Average low67°
Average precipitation0.01 in
Chance of precipitation8%
Record high115° (2020)
Record low55° (2000)
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 Crestline, 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 Crestline, 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.