Pokémon GO players in areas with less-than-ideal weather may be met with an Extreme Weather screen with the following warning message: “Pokémon seem to dislike these conditions. Weather conditions are potentially dangerous – be aware of your surroundings! Check your local weather service for details.” However, there is now a way to dismiss this warning and continue playing even during potentially dangerous weather. This can be accomplished by clicking the new I am Safe virtual button. For some reason, hazardous weather alerts sometimes appear during clear weather conditions as well, as shown in the screenshot above.
Pokémon GO hazardous weather alert appears even during clear weather conditions
Pokémon Blog 