In spring, water temperature needs to be in the low 40s. Peak hatches occur when the water temps hit 46 degrees and up. In summer, especially evenings, water temp needs to be in the 60 degree minimum. For fall mayflies, peak hatches will happen when the water temp is over 46 degrees.

What triggers a mayfly hatch?

Most mayflies rise to the surface of the lakes at night when the water is usually calm. They float on the surface until their wings are dry and then fly away to complete their life cycle. . ... If the cold weather returns the mayfly hatches will be more drawn out and take longer to complete.

Do mayflies hatch in winter?

Mayflies. Mayflies during winter primarily consist of Blue Wing Olives aka Baetis (BWO). These mayflies hatch when the water temps get above 38 degrees and are best between 40 – 44 F. They will also hatch during the warmest parts of the day 10 – 3 pm and can hatch on sunny days, cloudy days, windy days and snowy days.