Monthly outlook for Harmonville, PA: average high 87.9°, average low 70.3°. That is 3.3° above the climate normal for August. Precipitation is expected on 4 days (about 0.3 inches), against a normal of 6 days and 2.1 inches. The warmest day looks like 23 August (96.1°), the coolest 16 August (60.9°).
87.9°/70.3°
Average high / low
+3.3°
Above normal
4 / 6
Wet days / normal
0.3 in
Precipitation this month
Ten-day blocks vs climate normal
Period
Forecast high
Normal
Difference
9 August – 18 August
84.7°
82.7°
+1.1°
19 August – 28 August
93.4°
81.3°
+6.7°
29 August – 7 September
at normal
80°
—
August records over 66 years
99°9 August 2001All-time high
46.9°30 August 1986All-time low
Climate normals and records are computed from the nearest reference point — Bryn Mawr (5 mi).
Mon, 1089° / 73°0
89 °
Harmonville, Monday, 10 August
Light rain. High 89°, low 73°.
Pressure29.97 inHg
Wind6.4 mph W
Humidity39%
Visibility6.2 mi
Dew point61°
Tue, 1190° / 73°0.06
90 °
Harmonville, Tuesday, 11 August
Light rain. High 90°, low 73°.
Pressure29.88 inHg
Wind10 mph NW
Humidity48%
Visibility6.2 mi
Dew point63°
Wed, 1284° / 74°0.03
84 °
Harmonville, Wednesday, 12 August
Light rain. High 84°, low 74°.
Pressure29.77 inHg
Wind9.8 mph NW
Humidity58%
Visibility6.2 mi
Dew point65°
Thu, 1385° / 71°0.05
85 °
Harmonville, Thursday, 13 August
Light rain. High 85°, low 71°.
Pressure29.77 inHg
Wind13 mph NW
Humidity34%
Visibility—
Dew point52°
Fri, 1479° / 63°0
79 °
Harmonville, Friday, 14 August
Overcast. High 79°, low 63°.
Pressure30.03 inHg
Wind10 mph NW
Humidity33%
Visibility—
Dew point44°
Sat, 1579° / 61°0
79 °
Harmonville, Saturday, 15 August
Clear. High 79°, low 61°.
Pressure30.12 inHg
Wind12.5 mph NW
Humidity31%
Visibility—
Dew point42°
Sun, 1681° / 61°0
81 °
Harmonville, Sunday, 16 August
Overcast. High 81°, low 61°.
Pressure30.12 inHg
Wind6.6 mph NW
Humidity28%
Visibility—
Dew point42°
Mon, 1785° / 67°0
85 °
Harmonville, Monday, 17 August
Partly cloudy. High 85°, low 67°.
Pressure29.97 inHg
Wind9.9 mph SW
Humidity30%
Visibility—
Dew point48°
Tue, 1888° / 66°0
88 °
Harmonville, Tuesday, 18 August
Mostly clear. High 88°, low 66°.
Pressure30.00 inHg
Wind6.3 mph NW
Humidity35%
Visibility—
Dew point54°
Wed, 1991° / 71°0
91 °
Harmonville, Wednesday, 19 August
Clear. High 91°, low 71°.
Pressure30.06 inHg
Wind7.7 mph SE
Humidity30%
Visibility—
Dew point53°
Thu, 2092° / 71°0
92 °
Harmonville, Thursday, 20 August
Partly cloudy. High 92°, low 71°.
Pressure30.00 inHg
Wind7.4 mph S
Humidity30%
Visibility—
Dew point54°
Fri, 2195° / 74°0.08
95 °
Harmonville, Friday, 21 August
Light rain. High 95°, low 74°.
Pressure29.85 inHg
Wind10.7 mph SW
Humidity38%
Visibility—
Dew point63°
Sat, 2294° / 75°0.07
94 °
Harmonville, Saturday, 22 August
Light rain. High 94°, low 75°.
Pressure29.88 inHg
Wind7.8 mph NW
Humidity44%
Visibility—
Dew point66°
Sun, 2396° / 74°0
96 °
Harmonville, Sunday, 23 August
Clear. High 96°, low 74°.
Pressure29.91 inHg
Wind7.4 mph W
Humidity27%
Visibility—
Dew point54°
Mon, 2492° / 80°0.01
92 °
Harmonville, Monday, 24 August
Light rain. High 92°, low 80°.
Pressure29.94 inHg
Wind9.6 mph NW
Humidity56%
Visibility—
Dew point70°
From day 17 onward the outlook is built from 60-year climate statistics
Tue, 2582° / 65°0.06
82 °
Harmonville, Tuesday, 25 August
Climate normal for this date — 60-year average.
Average high82°
Average low65°
Average precipitation0.06 in
Chance of precipitation15%
Record high95° (1968)
Record low53° (1987)
Wed, 2682° / 65°0.06
82 °
Harmonville, Wednesday, 26 August
Climate normal for this date — 60-year average.
Average high82°
Average low65°
Average precipitation0.06 in
Chance of precipitation23%
Record high91° (1993)
Record low54° (1977)
Thu, 2783° / 66°0.18
83 °
Harmonville, Thursday, 27 August
Climate normal for this date — 60-year average.
Average high83°
Average low66°
Average precipitation0.18 in
Chance of precipitation33%
Record high93° (2020)
Record low55° (1963)
Fri, 2882° / 67°0.24
82 °
Harmonville, Friday, 28 August
Climate normal for this date — 60-year average.
Average high82°
Average low67°
Average precipitation0.24 in
Chance of precipitation47%
Record high96° (2024)
Record low56° (1968)
Sat, 2981° / 66°0.11
81 °
Harmonville, Saturday, 29 August
Climate normal for this date — 60-year average.
Average high81°
Average low66°
Average precipitation0.11 in
Chance of precipitation30%
Record high94° (2010)
Record low49° (1982)
Sun, 3081° / 65°0.06
81 °
Harmonville, Sunday, 30 August
Climate normal for this date — 60-year average.
Average high81°
Average low65°
Average precipitation0.06 in
Chance of precipitation27%
Record high94° (1973)
Record low47° (1986)
Mon, 3181° / 65°0.07
81 °
Harmonville, Monday, 31 August
Climate normal for this date — 60-year average.
Average high81°
Average low65°
Average precipitation0.07 in
Chance of precipitation20%
Record high95° (2010)
Record low50° (1976)
Tue, 0180° / 64°0.14
80 °
Harmonville, Tuesday, 1 September
Climate normal for this date — 60-year average.
Average high80°
Average low64°
Average precipitation0.14 in
Chance of precipitation32%
Record high94° (2010)
Record low54° (1967)
Wed, 0280° / 64°0.11
80 °
Harmonville, Wednesday, 2 September
Climate normal for this date — 60-year average.
Average high80°
Average low64°
Average precipitation0.11 in
Chance of precipitation33%
Record high94° (1980)
Record low52° (1970)
Thu, 0380° / 64°0.15
80 °
Harmonville, Thursday, 3 September
Climate normal for this date — 60-year average.
Average high80°
Average low64°
Average precipitation0.15 in
Chance of precipitation28%
Record high92° (2023)
Record low49° (1967)
Fri, 0480° / 64°0.09
80 °
Harmonville, Friday, 4 September
Climate normal for this date — 60-year average.
Average high80°
Average low64°
Average precipitation0.09 in
Chance of precipitation25%
Record high96° (2023)
Record low52° (1997)
Sat, 0579° / 64°0.08
79 °
Harmonville, Saturday, 5 September
Climate normal for this date — 60-year average.
Average high79°
Average low64°
Average precipitation0.08 in
Chance of precipitation25%
Record high96° (2023)
Record low52° (1997)
Sun, 0678° / 63°0.21
78 °
Harmonville, Sunday, 6 September
Climate normal for this date — 60-year average.
Average high78°
Average low63°
Average precipitation0.21 in
Chance of precipitation32%
Record high94° (2023)
Record low51° (1984)
Mon, 0780° / 62°0.11
80 °
Harmonville, Monday, 7 September
Climate normal for this date — 60-year average.
Average high80°
Average low62°
Average precipitation0.11 in
Chance of precipitation27%
Record high91° (2023)
Record low47° (1984)
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 Harmonville, PA 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 Harmonville, PA 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.