Monthly outlook for McDonald, TN: average high 91.2°, average low 69.2°. That is 2.7° above the climate normal for August. Precipitation is expected on 11 days (about 2.3 inches), against a normal of 6 days and 1.9 inches. The warmest day looks like 17 August (97.5°), the coolest 21 August (62.8°).
91.2°/69.2°
Average high / low
+2.7°
Above normal
11 / 6
Wet days / normal
2.3 in
Precipitation this month
Ten-day blocks vs climate normal
Period
Forecast high
Normal
Difference
8 August – 17 August
90.9°
86.2°
+2.6°
18 August – 27 August
91.8°
86.3°
+3°
28 August – 6 September
at normal
84.6°
—
August records over 66 years
103.1°16 August 2007All-time high
55.9°13 August 1964All-time low
Climate normals and records are computed from the nearest reference point — Chattanooga (15 mi).
Sun, 0992° / 69°0.08
92 °
McDonald, Sunday, 9 August
Light rain. High 92°, low 69°.
Pressure30.12 inHg
Wind3.1 mph S
Humidity55%
Visibility6.2 mi
Dew point70°
Mon, 1095° / 70°0.11
95 °
McDonald, Monday, 10 August
Rain. High 95°, low 70°.
Pressure30.12 inHg
Wind4.2 mph SW
Humidity57%
Visibility6.2 mi
Dew point70°
Tue, 1193° / 69°0.02
93 °
McDonald, Tuesday, 11 August
Light rain. High 93°, low 69°.
Pressure30.06 inHg
Wind5.3 mph SW
Humidity57%
Visibility6.2 mi
Dew point70°
Wed, 1294° / 70°0.31
94 °
McDonald, Wednesday, 12 August
Rain. High 94°, low 70°.
Pressure29.97 inHg
Wind8.2 mph W
Humidity51%
Visibility6.2 mi
Dew point70°
Thu, 1391° / 68°0.22
91 °
McDonald, Thursday, 13 August
Light rain. High 91°, low 68°.
Pressure29.97 inHg
Wind5.3 mph NE
Humidity53%
Visibility—
Dew point67°
Fri, 1479° / 72°0.12
79 °
McDonald, Friday, 14 August
Light rain. High 79°, low 72°.
Pressure30.09 inHg
Wind4.4 mph S
Humidity94%
Visibility—
Dew point73°
Sat, 1586° / 72°0.6
86 °
McDonald, Saturday, 15 August
Rain. High 86°, low 72°.
Pressure30.15 inHg
Wind9.8 mph NW
Humidity66%
Visibility—
Dew point72°
Sun, 1694° / 70°0
94 °
McDonald, Sunday, 16 August
Overcast. High 94°, low 70°.
Pressure30.12 inHg
Wind5.6 mph S
Humidity52%
Visibility—
Dew point68°
Mon, 1797° / 72°0.02
97 °
McDonald, Monday, 17 August
Light rain. High 97°, low 72°.
Pressure30.00 inHg
Wind8.3 mph W
Humidity40%
Visibility—
Dew point65°
Tue, 1897° / 69°0.26
97 °
McDonald, Tuesday, 18 August
Rain. High 97°, low 69°.
Pressure29.97 inHg
Wind9 mph N
Humidity46%
Visibility—
Dew point68°
Wed, 1993° / 69°0.11
93 °
McDonald, Wednesday, 19 August
Light rain. High 93°, low 69°.
Pressure29.91 inHg
Wind6 mph N
Humidity45%
Visibility—
Dew point65°
Thu, 2092° / 69°0
92 °
McDonald, Thursday, 20 August
Clear. High 92°, low 69°.
Pressure29.83 inHg
Wind10.4 mph N
Humidity46%
Visibility—
Dew point66°
Fri, 2180° / 63°0.15
80 °
McDonald, Friday, 21 August
Light rain. High 80°, low 63°.
Pressure30.03 inHg
Wind7.3 mph N
Humidity80%
Visibility—
Dew point63°
Sat, 2291° / 65°0.16
91 °
McDonald, Saturday, 22 August
Light rain. High 91°, low 65°.
Pressure30.00 inHg
Wind6.7 mph S
Humidity58%
Visibility—
Dew point65°
Sun, 2397° / 73°0
97 °
McDonald, Sunday, 23 August
Overcast. High 97°, low 73°.
Pressure30.03 inHg
Wind8.1 mph S
Humidity38%
Visibility—
Dew point63°
From day 17 onward the outlook is built from 60-year climate statistics
Mon, 2486° / 69°0.08
86 °
McDonald, Monday, 24 August
Climate normal for this date — 60-year average.
Average high86°
Average low69°
Average precipitation0.08 in
Chance of precipitation30%
Record high99° (1983)
Record low57° (1997)
Tue, 2586° / 69°0.11
86 °
McDonald, Tuesday, 25 August
Climate normal for this date — 60-year average.
Average high86°
Average low69°
Average precipitation0.11 in
Chance of precipitation30%
Record high98° (2023)
Record low59° (2015)
Wed, 2686° / 69°0.14
86 °
McDonald, Wednesday, 26 August
Climate normal for this date — 60-year average.
Average high86°
Average low69°
Average precipitation0.14 in
Chance of precipitation27%
Record high97° (2023)
Record low58° (1966)
Thu, 2786° / 69°0.1
86 °
McDonald, Thursday, 27 August
Climate normal for this date — 60-year average.
Average high86°
Average low69°
Average precipitation0.1 in
Chance of precipitation33%
Record high94° (1975)
Record low60° (1966)
Fri, 2886° / 69°0.1
86 °
McDonald, Friday, 28 August
Climate normal for this date — 60-year average.
Average high86°
Average low69°
Average precipitation0.1 in
Chance of precipitation30%
Record high97° (1990)
Record low56° (1967)
Sat, 2986° / 69°0.1
86 °
McDonald, Saturday, 29 August
Climate normal for this date — 60-year average.
Average high86°
Average low69°
Average precipitation0.1 in
Chance of precipitation38%
Record high96° (1990)
Record low57° (1968)
Sun, 3085° / 69°0.08
85 °
McDonald, Sunday, 30 August
Climate normal for this date — 60-year average.
Average high85°
Average low69°
Average precipitation0.08 in
Chance of precipitation40%
Record high96° (2024)
Record low58° (1965)
Mon, 3185° / 69°0.1
85 °
McDonald, Monday, 31 August
Climate normal for this date — 60-year average.
Average high85°
Average low69°
Average precipitation0.1 in
Chance of precipitation37%
Record high94° (1962)
Record low61° (1986)
Tue, 0185° / 68°0.14
85 °
McDonald, Tuesday, 1 September
Climate normal for this date — 60-year average.
Average high85°
Average low68°
Average precipitation0.14 in
Chance of precipitation42%
Record high94° (1993)
Record low60° (1967)
Wed, 0285° / 68°0.08
85 °
McDonald, Wednesday, 2 September
Climate normal for this date — 60-year average.
Average high85°
Average low68°
Average precipitation0.08 in
Chance of precipitation30%
Record high95° (2011)
Record low60° (1987)
Thu, 0384° / 68°0.13
84 °
McDonald, Thursday, 3 September
Climate normal for this date — 60-year average.
Average high84°
Average low68°
Average precipitation0.13 in
Chance of precipitation37%
Record high97° (2011)
Record low56° (2017)
Fri, 0484° / 67°0.15
84 °
McDonald, Friday, 4 September
Climate normal for this date — 60-year average.
Average high84°
Average low67°
Average precipitation0.15 in
Chance of precipitation37%
Record high97° (2019)
Record low59° (1967)
Sat, 0584° / 67°0.17
84 °
McDonald, Saturday, 5 September
Climate normal for this date — 60-year average.
Average high84°
Average low67°
Average precipitation0.17 in
Chance of precipitation30%
Record high96° (1975)
Record low55° (1997)
Sun, 0683° / 67°0.09
83 °
McDonald, Sunday, 6 September
Climate normal for this date — 60-year average.
Average high83°
Average low67°
Average precipitation0.09 in
Chance of precipitation28%
Record high96° (1990)
Record low55° (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 McDonald, TN 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 McDonald, TN 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.