In large parts of northwestern Götaland, the risk of forest and grass fires is high or very high, and locally extremely high, from midnight to 11 p.m. on Wednesday.
The same warning applies in parts of Blekinge, eastern Skåne and southern Öland between noon and 11 p.m.
In eastern Svealand and parts of Östergötland, the risk is high or very high between midnight and 11 p.m.
SMHI urges caution when lighting fires and using large machines that can create sparks.
According to the Civil Contingencies Agency, there are two water-scooping aircraft with a 180-minute readiness in Södermanland County until Friday afternoon.
In Kronoberg and Västra Götaland counties, there are two helicopters each with a 30-minute standby time.
