Monthly outlook for San Castle, FL: average high 91.8°, average low 82.3°. That is 2.7° above the climate normal for August. Precipitation is expected on 9 days (about 1.6 inches), against a normal of 14 days and 3.6 inches. The warmest day looks like 21 August (98.1°), the coolest 19 August (78.6°).
91.8°/82.3°
Average high / low
+2.7°
Above normal
9 / 14
Wet days / normal
1.6 in
Precipitation this month
Ten-day blocks vs climate normal
Period
Forecast high
Normal
Difference
8 August – 17 August
91.1°
86.9°
+2.3°
18 August – 27 August
93°
86.5°
+3.6°
28 August – 6 September
at normal
85.9°
—
August records over 66 years
97.9°20 August 2025All-time high
72.7°28 August 1984All-time low
Sun, 0991° / 81°0.04
91 °
San Castle, Sunday, 9 August
Light rain. High 91°, low 81°.
Pressure30.12 inHg
Wind11.2 mph SE
Humidity60%
Visibility6.2 mi
Dew point73°
Mon, 1092° / 79°0.03
92 °
San Castle, Monday, 10 August
Light rain. High 92°, low 79°.
Pressure30.15 inHg
Wind10.3 mph SE
Humidity58%
Visibility6.2 mi
Dew point73°
Tue, 1191° / 83°0
91 °
San Castle, Tuesday, 11 August
Clear. High 91°, low 83°.
Pressure30.12 inHg
Wind9.4 mph SE
Humidity56%
Visibility6.2 mi
Dew point71°
Wed, 1292° / 83°0
92 °
San Castle, Wednesday, 12 August
Clear. High 92°, low 83°.
Pressure30.06 inHg
Wind7.9 mph SE
Humidity53%
Visibility6.2 mi
Dew point71°
Thu, 1393° / 83°0.01
93 °
San Castle, Thursday, 13 August
Light rain. High 93°, low 83°.
Pressure30.03 inHg
Wind12 mph SE
Humidity49%
Visibility—
Dew point70°
Fri, 1491° / 84°0
91 °
San Castle, Friday, 14 August
Overcast. High 91°, low 84°.
Pressure30.15 inHg
Wind12.8 mph E
Humidity53%
Visibility—
Dew point71°
Sat, 1590° / 84°0.04
90 °
San Castle, Saturday, 15 August
Light rain. High 90°, low 84°.
Pressure30.15 inHg
Wind12.9 mph SE
Humidity58%
Visibility—
Dew point72°
Sun, 1691° / 83°0
91 °
San Castle, Sunday, 16 August
Partly cloudy. High 91°, low 83°.
Pressure30.09 inHg
Wind10.8 mph SE
Humidity52%
Visibility—
Dew point70°
Mon, 1789° / 83°0.34
89 °
San Castle, Monday, 17 August
Rain. High 89°, low 83°.
Pressure30.09 inHg
Wind7.6 mph NE
Humidity65%
Visibility—
Dew point72°
Tue, 1888° / 82°0.02
88 °
San Castle, Tuesday, 18 August
Light rain. High 88°, low 82°.
Pressure30.03 inHg
Wind9.5 mph E
Humidity60%
Visibility—
Dew point72°
Wed, 1992° / 79°0.24
92 °
San Castle, Wednesday, 19 August
Rain. High 92°, low 79°.
Pressure29.97 inHg
Wind9.6 mph W
Humidity51%
Visibility—
Dew point70°
Thu, 2096° / 81°0.3
96 °
San Castle, Thursday, 20 August
Rain. High 96°, low 81°.
Pressure29.91 inHg
Wind12.3 mph W
Humidity45%
Visibility—
Dew point69°
Fri, 2198° / 82°0.09
98 °
San Castle, Friday, 21 August
Light rain. High 98°, low 82°.
Pressure29.88 inHg
Wind12.3 mph W
Humidity47%
Visibility—
Dew point73°
Sat, 2294° / 84°0.1
94 °
San Castle, Saturday, 22 August
Light rain. High 94°, low 84°.
Pressure29.94 inHg
Wind12 mph NE
Humidity60%
Visibility—
Dew point76°
Sun, 2389° / 85°0.23
89 °
San Castle, Sunday, 23 August
Light rain. High 89°, low 85°.
Pressure30.03 inHg
Wind8.9 mph SE
Humidity64%
Visibility—
Dew point75°
From day 17 onward the outlook is built from 60-year climate statistics
Mon, 2486° / 77°0.3
86 °
San Castle, Monday, 24 August
Climate normal for this date — 60-year average.
Average high86°
Average low77°
Average precipitation0.3 in
Chance of precipitation83%
Record high90° (2014)
Record low74° (1996)
Tue, 2586° / 77°0.23
86 °
San Castle, Tuesday, 25 August
Climate normal for this date — 60-year average.
Average high86°
Average low77°
Average precipitation0.23 in
Chance of precipitation90%
Record high91° (2022)
Record low73° (2002)
Wed, 2686° / 77°0.26
86 °
San Castle, Wednesday, 26 August
Climate normal for this date — 60-year average.
Average high86°
Average low77°
Average precipitation0.26 in
Chance of precipitation87%
Record high92° (1998)
Record low74° (1984)
Thu, 2786° / 77°0.21
86 °
San Castle, Thursday, 27 August
Climate normal for this date — 60-year average.
Average high86°
Average low77°
Average precipitation0.21 in
Chance of precipitation85%
Record high92° (2011)
Record low74° (2017)
Fri, 2886° / 77°0.24
86 °
San Castle, Friday, 28 August
Climate normal for this date — 60-year average.
Average high86°
Average low77°
Average precipitation0.24 in
Chance of precipitation80%
Record high90° (2025)
Record low73° (1984)
Sat, 2986° / 77°0.21
86 °
San Castle, Saturday, 29 August
Climate normal for this date — 60-year average.
Average high86°
Average low77°
Average precipitation0.21 in
Chance of precipitation80%
Record high92° (2025)
Record low73° (1994)
Sun, 3086° / 77°0.2
86 °
San Castle, Sunday, 30 August
Climate normal for this date — 60-year average.
Average high86°
Average low77°
Average precipitation0.2 in
Chance of precipitation82%
Record high91° (2023)
Record low73° (1969)
Mon, 3186° / 77°0.27
86 °
San Castle, Monday, 31 August
Climate normal for this date — 60-year average.
Average high86°
Average low77°
Average precipitation0.27 in
Chance of precipitation82%
Record high94° (2025)
Record low74° (1976)
Tue, 0186° / 77°0.22
86 °
San Castle, Tuesday, 1 September
Climate normal for this date — 60-year average.
Average high86°
Average low77°
Average precipitation0.22 in
Chance of precipitation90%
Record high92° (1998)
Record low74° (1972)
Wed, 0285° / 77°0.22
85 °
San Castle, Wednesday, 2 September
Climate normal for this date — 60-year average.
Average high85°
Average low77°
Average precipitation0.22 in
Chance of precipitation80%
Record high91° (1998)
Record low73° (2022)
Thu, 0386° / 77°0.26
86 °
San Castle, Thursday, 3 September
Climate normal for this date — 60-year average.
Average high86°
Average low77°
Average precipitation0.26 in
Chance of precipitation80%
Record high90° (2015)
Record low74° (1967)
Fri, 0486° / 77°0.28
86 °
San Castle, Friday, 4 September
Climate normal for this date — 60-year average.
Average high86°
Average low77°
Average precipitation0.28 in
Chance of precipitation80%
Record high92° (2019)
Record low72° (1967)
Sat, 0586° / 77°0.38
86 °
San Castle, Saturday, 5 September
Climate normal for this date — 60-year average.
Average high86°
Average low77°
Average precipitation0.38 in
Chance of precipitation88%
Record high90° (2019)
Record low71° (2008)
Sun, 0686° / 77°0.28
86 °
San Castle, Sunday, 6 September
Climate normal for this date — 60-year average.
Average high86°
Average low77°
Average precipitation0.28 in
Chance of precipitation83%
Record high93° (2019)
Record low72° (2023)
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 San Castle, FL 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 San Castle, FL 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.