42.554°N, 92.401°W · station ALOthr · 132 years of record
63°F
COLDEST SEP 8 SINCE 2025
forecast low · Sep 8
7-Day Forecast
NWS NDFD forecast low temperature for Waterloo.
This Day in History
Every year's low on each of the next 7 forecast dates at Waterloo — toggle a day below. The forecast line shows where it lands; the ringed bar is the coldest on record.
Ranks
#129 / 131
coldest Sep 2 in 131 yrs of record
Coldest Sep 2 ever
38°F
set in 1946
Mildest Sep 2 ever
73°F
set in 1937
Forecast low 72°F — 129th coldest Sep 2 of 131 years · record 38°F (1946) · coldest since 2025.
Ranks
#130 / 131
coldest Sep 3 in 131 yrs of record
Coldest Sep 3 ever
36°F
set in 1974
Mildest Sep 3 ever
75°F
set in 1939
Forecast low 73°F — 130th coldest Sep 3 of 131 years · record 36°F (1974) · coldest since 2025.
Ranks
#132 / 131
coldest Sep 4 in 131 yrs of record
Coldest Sep 4 ever
34°F
set in 1974
Mildest Sep 4 ever
72°F
set in 2014
Forecast low 73°F — 132nd coldest Sep 4 of 131 years · record 34°F (1974) · coldest since 2025.
Ranks
#130 / 131
coldest Sep 5 in 131 yrs of record
Coldest Sep 5 ever
37°F
set in 1974
Mildest Sep 5 ever
73°F
set in 2023
Forecast low 70°F — 130th coldest Sep 5 of 131 years · record 37°F (1974) · coldest since 2025.
Ranks
#125 / 131
coldest Sep 6 in 131 yrs of record
Coldest Sep 6 ever
39°F
set in 1950
Mildest Sep 6 ever
73°F
set in 1990
Forecast low 69°F — 125th coldest Sep 6 of 131 years · record 39°F (1950) · coldest since 2025.
Ranks
#115 / 131
coldest Sep 7 in 131 yrs of record
Coldest Sep 7 ever
35°F
set in 1988
Mildest Sep 7 ever
77°F
set in 1939
Forecast low 66°F — 115th coldest Sep 7 of 131 years · record 35°F (1988) · coldest since 2025.
Ranks
#106 / 131
coldest Sep 8 in 131 yrs of record
Coldest Sep 8 ever
35°F
set in 1986
Mildest Sep 8 ever
72°F
set in 1985
Forecast low 63°F — 106th coldest Sep 8 of 131 years · record 35°F (1986) · coldest since 2025.
The hottest and coldest ever recorded at Waterloo in each calendar month, and for the whole 1895–2026 record — with the year each was set.
Month
Record High
Record Low
Jan
65°FJan 26, 2002
-34°FJan 16, 2009
Feb
78°FFeb 26, 2024
-31°FFeb 2, 1996
Mar
87°FMar 29, 1986
-34°FMar 1, 1962
Apr
100°FApr 22, 1980
-4°FApr 6, 1982
May
108°FMay 31, 1934
22°FMay 4, 1907
Jun
107°FJun 27, 1934
33°FJun 1, 1897
Jul
112°FJul 13, 1936
42°FJul 7, 1984
Aug
110°FAug 18, 1936
33°FAug 20, 1950
Sep
102°FSep 6, 1922
19°FSep 30, 1899
Oct
95°FOct 12, 1930
0°FOct 30, 1925
Nov
83°FNov 1, 1933
-17°FNov 26, 1977
Dec
74°FDec 15, 2021
-29°FDec 10, 1919
All-time
112°FJul 13, 1936
-34°FMar 1, 1962
2026 Records So Far
Records set or tied at Waterloo so far this year — through Aug 30.
Record Highs in 2026
3 broke
plus 1 tied — daily record highs set this year
Monthly high record this year: Mar (87°F)
Record Lows in 2026
0 broke
plus 0 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
80°F
record high minimum — the night it never cooled · Jul 31, 1917
Coldest high ever
-16°F
record low maximum — the day it never warmed · Feb 2, 1996
Month
Warmest low
Coldest high
Jan
43°FJan 1, 1897
-15°FJan 18, 1994
Feb
48°FFeb 20, 2017
-16°FFeb 2, 1996
Mar
62°FMar 18, 2012
-1°FMar 2, 2014
Apr
68°FApr 5, 1929
25°FApr 3, 1954
May
73°FMay 9, 1934
36°FMay 3, 2013
Jun
78°FJun 30, 2026
49°FJun 2, 1969
Jul
80°FJul 31, 1917
61°FJul 5, 1909
Aug
80°FAug 16, 1988
57°FAug 25, 1987
Sep
77°FSep 7, 1939
42°FSep 26, 1942
Oct
71°FOct 4, 2005
25°FOct 28, 1925
Nov
60°FNov 12, 1902
9°FNov 26, 1898
Dec
55°FDec 4, 2001
-15°FDec 24, 1983
All-time
80°FJul 31, 1917
-16°FFeb 2, 1996
Cold Streaks
Current run
0 days
consecutive days with a low ≤ 32°F
Longest ever
142 days
record run, ended Mar 28 2001
So far in 2026
84 days
days with a low ≤ 32°F this year
Climate Normals
Normal low & low by month, from Waterloo's own 1991–2020 record. Today's normal low: 54°F · forecast is +9° vs normal.
Waterloo'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 Waterloo's own record — the record low, the normal, and the full span ever seen. A shareable look at where the year stands.