This page is a single place to check Bonn climate: monthly averages. Bonn runs from 0.1 C in Jan to 18.0 C in Jul, a swing of 17.9 C. Rain is spread through the year, with Aug the wettest month at 2.57 mm/day and Apr the driest at 1.57 mm/day. Taken together that is roughly 770 mm of rain a year for the grid cell. Values come from a public open API; a successful result is cached so a later outage never blanks the page. Use the table for exact numbers, or the related pages below for neighbouring locations and periods.
Annual mean temperature 8.8 C
Warmest month Jul (18.0 C)
Coldest month Jan (0.1 C)
Wettest month Aug (2.57 mm/day)
All-time record high 38.7 C
All-time record low -18.6 C
Annual precipitation 770 mm / year
Coordinates 50.73438, 7.09549
Population 330,579
Average monthly temperature and rainfall in Bonn
Month
Mean temp (C)
Rain (mm/day)
Record high (C)
Record low (C)
Jan
0.1
2.04
11.8
-15.5
Feb
0.7
1.94
17.0
-18.6
Mar
3.9
1.82
19.8
-13.1
Apr
8.1
1.57
24.7
-5.9
May
12.1
2.31
29.0
-1.9
Jun
15.8
2.51
33.1
3.1
Jul
18.0
2.49
38.7
5.2
Aug
17.6
2.57
37.2
4.4
Sep
13.6
1.92
32.4
0.9
Oct
9.1
1.89
24.7
-5.2
Nov
4.7
2.11
17.7
-6.7
Dec
1.2
2.16
12.5
-14.1
What the Bonn climate table shows
Values are multi-decadal climatological averages for the 50.73438, 7.09549 grid cell, not a single year. Rain is the daily mean, so a value of 2.00 mm/day is about 60 mm across a 30-day month. Averages smooth over extremes, so use them for planning rather than for what to pack for next Tuesday.
Frequently asked questions
Why do the numbers differ from a weather app?
An app shows one location on one day. These are long-run averages, so they smooth out single hot or cold spells.
How much rain is 2.57 mm/day in a month?
Rain is recorded as a daily mean, so 2.57 mm/day is roughly 78 mm across a 30-day month.