Tonsberg, Norway experiences cold winters with temperatures often dropping below freezing, averaging around 0°C in January and February. As spring arrives in March and April, temperatures gradually rise, averaging 4-5°C, with occasional warmer days reaching up to 18°C. Summer months of June to August bring pleasant warmth, with average highs around 15-16°C, while September sees a return to milder conditions, similar to those in May. Autumn is characterized by cool temperatures, often near or below freezing, and winter's chill returns in November and December. Overall, the region has distinct seasonal patterns, with cold winters and mild summers, but relatively moderate temperatures throughout the year.