The climate of Jönköping is Baltic, that is, moderately continental, with cold winters, during which the average temperature is a few degrees below freezing, and mild summers.
The city is located in southern Sweden, on the shores of Lake Vättern.
The average temperature of the coldest month (January) is of -2.5 °C (28 °F), that of the warmest month (July) is of 16.4 °C (61 °F). However, during polar cold spells, the temperature can drop to -25 °C (-13 °F) or below, while in summer, it can reach 28/30 °C (82/86 °F), although rarely. Here are the average temperatures.
Jönköping - Average temperatures
Min (°C)-5-5-40481110730-3
Max (°C)0151116202220161052
Min (°F)232325323946525045373227
Max (°F)323441526168726861504136

Precipitation amounts to 635 millimeters (25 inches) per year: so, it is at an intermediate level. It ranges from 30 mm (1.2 in) in the driest months (February, March, April) to 85 mm (3.3 in) in the wettest (August). Here is the average precipitation.
Jönköping - Average precipitation


Best Time

The best time to visit Jönköping is the summer, from June to August, since it is the mildest season. However, you must take into account some rainy days and a bit of cold at night.