From 51.5°N: best August to September, peaking at 69° at 22:00.
- JanJanuary: 3 degrees at 22:00
- FebFebruary: -5 degrees at 22:00
- MarMarch: -6 degrees at 22:00
- AprApril: 1 degrees at 22:00
- MayMay: 13 degrees at 22:00
- JunJune: 31 degrees at 22:00
- JulJuly: 49 degrees at 22:00
- AugAugust: 66 degrees at 22:00
- SepSeptember: 69 degrees at 22:00
- OctOctober: 54 degrees at 22:00
- NovNovember: 35 degrees at 22:00
- DecDecember: 18 degrees at 22:00
Altitude at 22:00 local time on the 15th of each month. Twilight, moon and weather are your problem.