April weather forecast
Thunder Bay, Canada

In April, the weather in Thunder Bay experiences noticeable warming. The last of winter’s snow melts away, replaced by increased rainfall at 37mm (1.46"). The longer hours of daylight accompanied by reduced snowfall facilitate the awakening of the city’s flora. This change makes it an ideal time for outdoor exploration and enjoying the refreshing spring air.

Temperature

Thunder Bay's weather experiences a significant temperature rise with the arrival of April, soaring from a cold 0.6°C (33.1°F) in March to a chilly 9.2°C (48.6°F). The average low-temperature reading in April for Thunder Bay reflects a significant fall from the daytime highs, stabilizing at a freezing cold -3.2°C (26.2°F).

Rainfall

In Thunder Bay, Canada, in April, during 7.1 rainfall days, 37mm (1.46") of precipitation is typically accumulated. Throughout the year, there are 92.6 rainfall days, and 547mm (21.54") of precipitation is accumulated.

Snowfall

Months with snowfall in Thunder Bay are January through May, September through December. In Thunder Bay, Canada, in April, snow falls for 4 days, with typically accumulated 103mm (4.06") of snow. Throughout the year, there are 62.7 snowfall days, and 1631mm (64.21") of snow is accumulated.

Sea temperature

The months with the coldest seawater are January through April, with an average sea temperature of 2°C (35.6°F).
Note: In connection with swimming, this state is severely cold, hazardous, and lethal. Without protective insulated waterproof garments, hypothermia sets in rapidly.

Daylight

In Thunder Bay, Canada, the average length of the day in April is 13h and 43min.
On the first day of the month, sunrise is at 7:33 am and sunset at 8:28 pm. On the last day of April, in Thunder Bay, Canada, sunrise is at 6:37 am and sunset at 9:10 pm EDT.

Sunshine

The average sunshine in April in Thunder Bay, Canada, is 7.1h.

UV index

The average daily maximum UV index in April is 4. A UV Index of 3 to 5 symbolizes a moderate threat to health from unsafe exposure to UV radiation for the average person.
Note: In April, the maximum UV index of 4 translates into these guidelines:
Act with care - The suggestion to avoid sunburn is emphasized. Solar radiation is at its peak intensity during midday, so it's advisable to stay indoors or in the shade. Clothes that are both tight-knit and comfortably loose are prime choices for sun protection. Be mindful! The reflection from snow can increase the Sun's UV radiation nearly twice.