Monthly outlook for Harney, SD: average high 58.7°, average low 40.7°. That is 0.4° below the climate normal for October. Precipitation is expected on 4 days (about 0.6 inches), against a normal of 3 days and 0.8 inches. The warmest day looks like 17 October (71.6°), the coolest 16 October (26.5°).
58.7°/40.7°
Average high / low
−0.4°
Below normal
4 / 3
Wet days / normal
0.6 in
Precipitation this month
Ten-day blocks vs climate normal
Period
Forecast high
Normal
Difference
11 October – 20 October
59.5°
60.3°
-0.4°
21 October – 30 October
57.2°
56.6°
+0.4°
31 October – 9 November
at normal
51°
—
October records over 66 years
90.3°3 October 2025All-time high
-4.2°26 October 2020All-time low
Climate normals and records are computed from the nearest reference point — Hermosa (10 mi).
Mon, 1252° / 41°0.04
52 °
Harney, Monday, 12 October
Light rain. High 52°, low 41°.
Pressure29.80 inHg
Wind4.2 mph NE
Humidity71%
Visibility6.2 mi
Dew point47°
Tue, 1349° / 37°0.37
49 °
Harney, Tuesday, 13 October
Rain. High 49°, low 37°.
Pressure30.03 inHg
Wind4.4 mph SE
Humidity79%
Visibility6.2 mi
Dew point40°
Wed, 1451° / 40°0.04
51 °
Harney, Wednesday, 14 October
Light rain. High 51°, low 40°.
Pressure30.18 inHg
Wind4.6 mph SE
Humidity68%
Visibility6.2 mi
Dew point39°
Thu, 1553° / 37°0.13
53 °
Harney, Thursday, 15 October
Rain. High 53°, low 37°.
Pressure30.39 inHg
Wind17.7 mph N
Humidity38%
Visibility6.2 mi
Dew point19°
Fri, 1658° / 27°0
58 °
Harney, Friday, 16 October
Clear. High 58°, low 27°.
Pressure30.53 inHg
Wind14.6 mph SW
Humidity29%
Visibility—
Dew point21°
Sat, 1772° / 47°0
72 °
Harney, Saturday, 17 October
Clear. High 72°, low 47°.
Pressure29.88 inHg
Wind15.6 mph SW
Humidity21%
Visibility—
Dew point26°
Sun, 1871° / 53°0
71 °
Harney, Sunday, 18 October
Clear. High 71°, low 53°.
Pressure29.91 inHg
Wind8.9 mph W
Humidity18%
Visibility—
Dew point23°
Mon, 1969° / 49°0
69 °
Harney, Monday, 19 October
Clear. High 69°, low 49°.
Pressure29.91 inHg
Wind9.6 mph SE
Humidity24%
Visibility—
Dew point26°
Tue, 2065° / 42°0
65 °
Harney, Tuesday, 20 October
Overcast. High 65°, low 42°.
Pressure29.50 inHg
Wind29.3 mph SW
Humidity34%
Visibility—
Dew point35°
Wed, 2152° / 38°0
52 °
Harney, Wednesday, 21 October
Overcast. High 52°, low 38°.
Pressure29.88 inHg
Wind14.7 mph NW
Humidity33%
Visibility—
Dew point22°
Thu, 2256° / 38°0
56 °
Harney, Thursday, 22 October
Clear. High 56°, low 38°.
Pressure30.03 inHg
Wind19.4 mph NW
Humidity31%
Visibility—
Dew point21°
Fri, 2362° / 38°0
62 °
Harney, Friday, 23 October
Clear. High 62°, low 38°.
Pressure30.03 inHg
Wind12.5 mph S
Humidity33%
Visibility—
Dew point26°
Sat, 2468° / 48°0
68 °
Harney, Saturday, 24 October
Overcast. High 68°, low 48°.
Pressure29.53 inHg
Wind8.9 mph E
Humidity17%
Visibility—
Dew point19°
Sun, 2552° / 39°0
52 °
Harney, Sunday, 25 October
Overcast. High 52°, low 39°.
Pressure29.91 inHg
Wind11.4 mph NW
Humidity45%
Visibility—
Dew point30°
Mon, 2653° / 34°0
53 °
Harney, Monday, 26 October
Mostly clear. High 53°, low 34°.
Pressure30.03 inHg
Wind8.5 mph E
Humidity39%
Visibility—
Dew point26°
From day 17 onward the outlook is built from 60-year climate statistics
Tue, 2756° / 35°0.03
56 °
Harney, Tuesday, 27 October
Climate normal for this date — 60-year average.
Average high56°
Average low35°
Average precipitation0.03 in
Chance of precipitation23%
Record high78° (2016)
Record low8° (2020)
Wed, 2856° / 35°0.07
56 °
Harney, Wednesday, 28 October
Climate normal for this date — 60-year average.
Average high56°
Average low35°
Average precipitation0.07 in
Chance of precipitation22%
Record high78° (2016)
Record low13° (1991)
Thu, 2954° / 35°0.07
54 °
Harney, Thursday, 29 October
Climate normal for this date — 60-year average.
Average high54°
Average low35°
Average precipitation0.07 in
Chance of precipitation35%
Record high78° (1968)
Record low8° (1991)
Fri, 3052° / 34°0.04
52 °
Harney, Friday, 30 October
Climate normal for this date — 60-year average.
Average high52°
Average low34°
Average precipitation0.04 in
Chance of precipitation22%
Record high77° (1968)
Record low3° (1991)
Sat, 3152° / 34°0.03
52 °
Harney, Saturday, 31 October
Climate normal for this date — 60-year average.
Average high52°
Average low34°
Average precipitation0.03 in
Chance of precipitation15%
Record high74° (1990)
Record low3° (1991)
Sun, 0151° / 33°0.05
51 °
Harney, Sunday, 1 November
Climate normal for this date — 60-year average.
Average high51°
Average low33°
Average precipitation0.05 in
Chance of precipitation18%
Record high72° (1965)
Record low3° (2002)
Mon, 0251° / 32°0.04
51 °
Harney, Monday, 2 November
Climate normal for this date — 60-year average.
Average high51°
Average low32°
Average precipitation0.04 in
Chance of precipitation20%
Record high75° (2008)
Record low-2° (1991)
Tue, 0351° / 33°0.04
51 °
Harney, Tuesday, 3 November
Climate normal for this date — 60-year average.
Average high51°
Average low33°
Average precipitation0.04 in
Chance of precipitation20%
Record high71° (2020)
Record low2° (1991)
Wed, 0453° / 32°0.01
53 °
Harney, Wednesday, 4 November
Climate normal for this date — 60-year average.
Average high53°
Average low32°
Average precipitation0.01 in
Chance of precipitation10%
Record high76° (1978)
Record low7° (1995)
Thu, 0552° / 33°0.03
52 °
Harney, Thursday, 5 November
Climate normal for this date — 60-year average.
Average high52°
Average low33°
Average precipitation0.03 in
Chance of precipitation13%
Record high76° (2020)
Record low1° (2003)
Fri, 0651° / 32°0.04
51 °
Harney, Friday, 6 November
Climate normal for this date — 60-year average.
Average high51°
Average low32°
Average precipitation0.04 in
Chance of precipitation13%
Record high75° (2020)
Record low-3° (2003)
Sat, 0752° / 32°0.03
52 °
Harney, Saturday, 7 November
Climate normal for this date — 60-year average.
Average high52°
Average low32°
Average precipitation0.03 in
Chance of precipitation13%
Record high75° (1999)
Record low3° (1991)
Sun, 0850° / 31°0.06
50 °
Harney, Sunday, 8 November
Climate normal for this date — 60-year average.
Average high50°
Average low31°
Average precipitation0.06 in
Chance of precipitation20%
Record high77° (1999)
Record low3° (2003)
Mon, 0946° / 29°0.06
46 °
Harney, Monday, 9 November
Climate normal for this date — 60-year average.
Average high46°
Average low29°
Average precipitation0.06 in
Chance of precipitation25%
Record high74° (2016)
Record low-3° (1966)
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 Harney, SD 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 Harney, SD 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.