Monthly outlook for Sinai, SD: average high 85.7°, average low 58.7°. That is 3.9° above the climate normal for August. Precipitation is expected on 7 days (about 0.6 inches), against a normal of 5 days and 1.9 inches. The warmest day looks like 10 August (96.8°), the coolest 21 August (50.7°).
85.7°/58.7°
Average high / low
+3.9°
Above normal
7 / 5
Wet days / normal
0.6 in
Precipitation this month
Ten-day blocks vs climate normal
Period
Forecast high
Normal
Difference
8 August – 17 August
86.2°
78.7°
+4.2°
18 August – 27 August
84.8°
78.5°
+3.5°
28 August – 6 September
at normal
77.1°
—
August records over 66 years
100.4°13 August 1965All-time high
44.4°21 August 2004All-time low
Climate normals and records are computed from the nearest reference point — Nunda (6 mi).
Sun, 0981° / 63°0.06
81 °
Sinai, Sunday, 9 August
Light rain. High 81°, low 63°.
Pressure29.80 inHg
Wind9 mph NE
Humidity55%
Visibility6.2 mi
Dew point66°
Mon, 1097° / 60°0.06
97 °
Sinai, Monday, 10 August
Rain. High 97°, low 60°.
Pressure29.83 inHg
Wind12.1 mph SE
Humidity37%
Visibility6.2 mi
Dew point59°
Tue, 1188° / 62°0.05
88 °
Sinai, Tuesday, 11 August
Rain. High 88°, low 62°.
Pressure29.83 inHg
Wind9.3 mph N
Humidity45%
Visibility6.2 mi
Dew point61°
Wed, 1289° / 61°0
89 °
Sinai, Wednesday, 12 August
Clear. High 89°, low 61°.
Pressure29.91 inHg
Wind11.6 mph E
Humidity26%
Visibility6.2 mi
Dew point47°
Thu, 1378° / 59°0.09
78 °
Sinai, Thursday, 13 August
Light rain. High 78°, low 59°.
Pressure30.00 inHg
Wind10.5 mph E
Humidity52%
Visibility—
Dew point53°
Fri, 1487° / 56°0
87 °
Sinai, Friday, 14 August
Overcast. High 87°, low 56°.
Pressure30.09 inHg
Wind13.4 mph E
Humidity29%
Visibility—
Dew point44°
Sat, 1583° / 61°0
83 °
Sinai, Saturday, 15 August
Overcast. High 83°, low 61°.
Pressure30.12 inHg
Wind13.4 mph SE
Humidity34%
Visibility—
Dew point48°
Sun, 1687° / 58°0
87 °
Sinai, Sunday, 16 August
Overcast. High 87°, low 58°.
Pressure30.06 inHg
Wind6.3 mph SW
Humidity42%
Visibility—
Dew point56°
Mon, 1792° / 62°0.14
92 °
Sinai, Monday, 17 August
Light rain. High 92°, low 62°.
Pressure29.97 inHg
Wind9.2 mph SW
Humidity45%
Visibility—
Dew point59°
Tue, 1896° / 65°0
96 °
Sinai, Tuesday, 18 August
Partly cloudy. High 96°, low 65°.
Pressure29.91 inHg
Wind17.9 mph SW
Humidity24%
Visibility—
Dew point47°
Wed, 1979° / 57°0.03
79 °
Sinai, Wednesday, 19 August
Light rain. High 79°, low 57°.
Pressure30.12 inHg
Wind17.8 mph NE
Humidity34%
Visibility—
Dew point42°
Thu, 2073° / 58°0.04
73 °
Sinai, Thursday, 20 August
Light rain. High 73°, low 58°.
Pressure30.15 inHg
Wind10.6 mph S
Humidity71%
Visibility—
Dew point52°
Fri, 2184° / 51°0.02
84 °
Sinai, Friday, 21 August
Light rain. High 84°, low 51°.
Pressure29.91 inHg
Wind18.2 mph S
Humidity31%
Visibility—
Dew point42°
Sat, 2289° / 59°0.07
89 °
Sinai, Saturday, 22 August
Light rain. High 89°, low 59°.
Pressure29.77 inHg
Wind19 mph W
Humidity34%
Visibility—
Dew point50°
Sun, 2387° / 54°0
87 °
Sinai, Sunday, 23 August
Clear. High 87°, low 54°.
Pressure29.94 inHg
Wind8.2 mph E
Humidity27%
Visibility—
Dew point40°
From day 17 onward the outlook is built from 60-year climate statistics
Mon, 2479° / 63°0.09
79 °
Sinai, Monday, 24 August
Climate normal for this date — 60-year average.
Average high79°
Average low63°
Average precipitation0.09 in
Chance of precipitation20%
Record high91° (2020)
Record low49° (1966)
Tue, 2579° / 62°0.09
79 °
Sinai, Tuesday, 25 August
Climate normal for this date — 60-year average.
Average high79°
Average low62°
Average precipitation0.09 in
Chance of precipitation35%
Record high93° (1991)
Record low48° (1964)
Wed, 2679° / 62°0.13
79 °
Sinai, Wednesday, 26 August
Climate normal for this date — 60-year average.
Average high79°
Average low62°
Average precipitation0.13 in
Chance of precipitation33%
Record high94° (1976)
Record low50° (2025)
Thu, 2778° / 62°0.06
78 °
Sinai, Thursday, 27 August
Climate normal for this date — 60-year average.
Average high78°
Average low62°
Average precipitation0.06 in
Chance of precipitation20%
Record high91° (1973)
Record low47° (1986)
Fri, 2878° / 62°0.08
78 °
Sinai, Friday, 28 August
Climate normal for this date — 60-year average.
Average high78°
Average low62°
Average precipitation0.08 in
Chance of precipitation28%
Record high94° (2012)
Record low46° (1965)
Sat, 2978° / 61°0.05
78 °
Sinai, Saturday, 29 August
Climate normal for this date — 60-year average.
Average high78°
Average low61°
Average precipitation0.05 in
Chance of precipitation25%
Record high95° (2012)
Record low50° (1988)
Sun, 3078° / 60°0.09
78 °
Sinai, Sunday, 30 August
Climate normal for this date — 60-year average.
Average high78°
Average low60°
Average precipitation0.09 in
Chance of precipitation23%
Record high94° (2012)
Record low46° (2009)
Mon, 3177° / 61°0.07
77 °
Sinai, Monday, 31 August
Climate normal for this date — 60-year average.
Average high77°
Average low61°
Average precipitation0.07 in
Chance of precipitation23%
Record high88° (2013)
Record low45° (1992)
Tue, 0177° / 60°0.09
77 °
Sinai, Tuesday, 1 September
Climate normal for this date — 60-year average.
Average high77°
Average low60°
Average precipitation0.09 in
Chance of precipitation22%
Record high93° (1970)
Record low45° (1965)
Wed, 0277° / 60°0.09
77 °
Sinai, Wednesday, 2 September
Climate normal for this date — 60-year average.
Average high77°
Average low60°
Average precipitation0.09 in
Chance of precipitation22%
Record high94° (2023)
Record low44° (1972)
Thu, 0376° / 60°0.04
76 °
Sinai, Thursday, 3 September
Climate normal for this date — 60-year average.
Average high76°
Average low60°
Average precipitation0.04 in
Chance of precipitation22%
Record high92° (2023)
Record low40° (1974)
Fri, 0477° / 59°0.07
77 °
Sinai, Friday, 4 September
Climate normal for this date — 60-year average.
Average high77°
Average low59°
Average precipitation0.07 in
Chance of precipitation18%
Record high95° (2023)
Record low44° (2025)
Sat, 0576° / 60°0.08
76 °
Sinai, Saturday, 5 September
Climate normal for this date — 60-year average.
Average high76°
Average low60°
Average precipitation0.08 in
Chance of precipitation23%
Record high90° (1990)
Record low42° (1965)
Sun, 0677° / 59°0.06
77 °
Sinai, Sunday, 6 September
Climate normal for this date — 60-year average.
Average high77°
Average low59°
Average precipitation0.06 in
Chance of precipitation18%
Record high96° (1970)
Record low44° (2025)
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 Sinai, 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 Sinai, 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.