Chironomid (bloodworm) main emergence

Window

Typical: 20 Feb – 15 Mar (2026)

Water temp trigger

~6.0°C

Latitude range

50-52°N

Lunar-influenced; spring trigger. Often the first signal that 'biological spring' is under way underwater.

Relevance to fishing

First major aquatic protein flush of the year. Roach and bream gorge on the larvae and emergers, often well before anglers expect them to feed. Match the hatch with size 18-22 buzzers or pinkie maggot.

Phenology chain

Triggered by

• Canadian pondweed growth resumes typically 21d before (range 14 – 30d)

Triggers

• Perch spawning typically 28d after (range 21 – 40d)