43.578°N, 96.754°W · station FSDthr · 134 years of record
64°F
COLDEST SEP 2 SINCE 2025
forecast low · Sep 2
7-Day Forecast
NWS NDFD forecast low temperature for Sioux Falls.
This Day in History
Every year's low on each of the next 7 forecast dates at Sioux Falls — toggle a day below. The forecast line shows where it lands; the ringed bar is the coldest on record.
Ranks
#105 / 133
coldest Sep 2 in 133 yrs of record
Coldest Sep 2 ever
35°F
set in 1893
Mildest Sep 2 ever
73°F
set in 1937
Forecast low 64°F — 105th coldest Sep 2 of 133 years · record 35°F (1893) · coldest since 2025.
Ranks
#127 / 133
coldest Sep 3 in 133 yrs of record
Coldest Sep 3 ever
31°F
set in 1974
Mildest Sep 3 ever
74°F
set in 1971
Forecast low 69°F — 127th coldest Sep 3 of 133 years · record 31°F (1974) · coldest since 2025.
Ranks
#131 / 133
coldest Sep 4 in 133 yrs of record
Coldest Sep 4 ever
36°F
set in 1902
Mildest Sep 4 ever
74°F
set in 1960
Forecast low 72°F — 131st coldest Sep 4 of 133 years · record 36°F (1902) · coldest since 2025.
Ranks
#132 / 133
coldest Sep 5 in 133 yrs of record
Coldest Sep 5 ever
34°F
set in 1909
Mildest Sep 5 ever
72°F
set in 1922
Forecast low 70°F — 132nd coldest Sep 5 of 133 years · record 34°F (1909) · coldest since 2025.
Ranks
#124 / 133
coldest Sep 6 in 133 yrs of record
Coldest Sep 6 ever
37°F
set in 1898
Mildest Sep 6 ever
73°F
set in 1922
Forecast low 69°F — 124th coldest Sep 6 of 133 years · record 37°F (1898) · coldest since 2025.
Ranks
#118 / 133
coldest Sep 7 in 133 yrs of record
Coldest Sep 7 ever
30°F
set in 1895
Mildest Sep 7 ever
71°F
set in 1960
Forecast low 66°F — 118th coldest Sep 7 of 133 years · record 30°F (1895) · coldest since 2025.
Ranks
#115 / 133
coldest Sep 8 in 133 yrs of record
Coldest Sep 8 ever
37°F
set in 1898
Mildest Sep 8 ever
71°F
set in 1933
Forecast low 65°F — 115th coldest Sep 8 of 133 years · record 37°F (1898) · coldest since 2025.
The hottest and coldest ever recorded at Sioux Falls in each calendar month, and for the whole 1893–2026 record — with the year each was set.
Month
Record High
Record Low
Jan
66°FJan 24, 1981
-38°FJan 12, 1912
Feb
70°FFeb 23, 1958
-42°FFeb 9, 1899
Mar
89°FMar 21, 2026
-23°FMar 11, 1948
Apr
98°FApr 28, 1910
4°FApr 3, 1936
May
104°FMay 30, 1934
17°FMay 4, 1967
Jun
110°FJun 21, 1988
32°FJun 7, 1897
Jul
110°FJul 17, 1936
34°FJul 9, 1895
Aug
109°FAug 24, 1936
34°FAug 29, 1893
Sep
104°FSep 4, 1913
13°FSep 29, 1899
Oct
95°FOct 1, 2023
-5°FOct 29, 1925
Nov
82°FNov 6, 2020
-17°FNov 14, 1959
Dec
63°FDec 1, 1998
-31°FDec 29, 1917
All-time
110°FJul 17, 1936
-42°FFeb 9, 1899
2026 Records So Far
Records set or tied at Sioux Falls so far this year — through Aug 30.
Record Highs in 2026
4 broke
plus 2 tied — daily record highs set this year
Monthly high record this year: Mar (89°F)
Record Lows in 2026
0 broke
plus 1 tied — daily record lows set this year
Record Warm Nights & Cold Days
Two more daily records, kept separate from the rankings: the warmest a night has ever stayed (record high minimum) and the coldest a day has ever gotten (record low maximum) — the flip side of the usual record high and low.
Warmest low ever
81°F
record high minimum — the night it never cooled · Jul 12, 1936
Coldest high ever
-23°F
record low maximum — the day it never warmed · Feb 8, 1899
Month
Warmest low
Coldest high
Jan
43°FJan 25, 1944
-18°FJan 24, 1897
Feb
44°FFeb 23, 2000
-23°FFeb 8, 1899
Mar
63°FMar 18, 2012
-4°FMar 1, 1919
Apr
65°FApr 24, 1924
22°FApr 1, 1975
May
77°FMay 31, 1934
36°FMay 5, 1944
Jun
78°FJun 21, 1988
46°FJun 1, 1946
Jul
81°FJul 12, 1936
58°FJul 18, 1912
Aug
81°FAug 14, 1938
57°FAug 25, 1987
Sep
77°FSep 14, 1939
41°FSep 28, 1985
Oct
73°FOct 1, 2023
19°FOct 29, 1925
Nov
59°FNov 8, 2020
-2°FNov 29, 1896
Dec
44°FDec 1, 1962
-16°FDec 21, 1989
All-time
81°FJul 12, 1936
-23°FFeb 8, 1899
Cold Streaks
Current run
0 days
consecutive days with a low ≤ 32°F
Longest ever
157 days
record run, ended Apr 10 1899
So far in 2026
97 days
days with a low ≤ 32°F this year
Climate Normals
Normal low & low by month, from Sioux Falls's own 1991–2020 record. Today's normal low: 58°F · forecast is +6° vs normal.
Sioux Falls's observed daily low for the last six weeks — a white ring marks any day that broke or tied its daily record for that date.
2026 So Far
Every day this year against Sioux Falls's own record — the record low, the normal, and the full span ever seen. A shareable look at where the year stands.