Avon dawns: May trout windows
Ephemera danica nymphs line the riffles on the River Avon below Salisbury at first light in May

What is biting this morning
Brown trout are keyed to nymphs before the full Mayfly emergence. Large Dark Olives still show from April. Small Grannom and early Blue-winged Olives start to appear later in the month. Dawn gives solid subsurface feeding; surface activity usually peaks later in the day.
Tactics at first light
Work upstream nymphs across the riffles and along undercut banks. A Pheasant Tail Nymph in sizes 14-16 is the go-to for Mayfly and Olive nymphs. Fish tight to the riverbed; long, natural drifts win more takes than flashy indicators. Hold back expectation for a hatch; patience with depth and drift produces the best dawn action.
Dry-fly windows & water
When light improves—midday windows (roughly 12:00–14:00 UTC) on chalkstreams—switch to large Ephemera imitations for emergers and spinners. For lingering olives use size 16-18 dries. Typical Avon notes: clear, low flows after a dry spell; trout shelter in deeper tails, seams and behind willow roots. Best tackle is a 9-foot, 4-weight fly rod with fine tippets and a chewed upstream presentation.
Recommended: lightweight trout rod