Almanac for 2026 · No. 10 · Autumn, October

Curamenti

A slow almanac of the fly rod

The hatch chart · Mayfly

Medium Olive

Baetis vernus

Fig. An upwinged fly (Ephemeroptera): wings held upright, two or three long tails.
Natural’s size
Hook 16
Time of day
Late morning into afternoon
At its peak
May, June
Fly to try
Greenwell’s Glory or Kite’s Imperial, size 16

The year

  1. JJanuary: not expected
  2. FFebruary: not expected
  3. MMarch: not expected
  4. AApril: not expected
  5. MMay: main hatch
  6. JJune: main hatch
  7. JJuly: some about
  8. AAugust: some about
  9. SSeptember: some about
  10. OOctober: not expected
  11. NNovember: not expected
  12. DDecember: not expected

In the hand

The standard summer olive: 7–8 mm, two tails, medium-grey wings and a body of brownish olive that looks paler and yellower than the large dark olive of spring. If in doubt on a summer morning, it is probably this.

On the river

Common on weedy lowland rivers and chalk streams. Hatches are steady rather than dramatic and can last for hours, which makes for calm, confident rises.

Flies that match it

Greenwell’s Glory

Dry · hook 12–16

Kite’s Imperial

Dry · hook 14–16

Parachute Adams

Dry · hook 12–20

Pheasant Tail Nymph

Nymph · hook 12–18