Although winters are cold, average temperatures generally remain above 0 °C for much of the year. Summers are pleasantly warm, and precipitation occurs throughout the year.

Due to the city’s high northerly latitude, the length of the day varies widely from more than 18 hours around midsummer to only around 6 hours in late December.

The nights from late May until mid-July are bright even when cloudy. Stockholm has relatively mild weather compared to other locations at a similar latitude, or even farther south.

With an average of 1900 hours of sunshine per year, it is also one of the sunniest cities in Northern Europe, receiving more sunshine than Paris, London and a few other major European cities of a more southerly latitude.

In spite of its mild climate, Stockholm is located further north than parts of Canada that are above the Arctic tree line at sea level.

Summers average daytime high temperatures of 20–25 °C and lows of around 13 °C, but temperatures can reach 30 °C on some days.

Days between 25 °C and 30 °C are relatively common especially in July and August. Night-time lows of above 20 °C are rare, and hot summer nights vary from 17 to 18 °C.

Winters generally bring cloudy weather with the most precipitation falling in December and January (as either rain or snow). The average winter temperatures range from −3 to −1 °C, and occasionally drop below −20 °C in the outskirts of the city. Spring and autumn are generally cool to mild.

Snowfall occurs mainly from December through March. Snowfall may occasionally occur in late October as well as in April.

In Stockholm, the aurora borealis can occasionally be observed.