RE:Troutin in da rain
I think the general rule will be cold water, trout not rising but hungry and searching for something to kill in the cover of overcast skies.
I'm no trout messiah but can share a few rainy days I remember...
Cliff pond, left of ramp, sandy beach with sharp drop... full sinking 5wt WF line and short leader, tan biot beadhead stone -or- black stone, crawl the stone up the sandy drop and hang on! The wind was blowing hard right in my face and the rain was running down my neck and I thought I would be wasting my time... caught trout after trout. Walk along the drop and fish it just off the bottom. Cobble bottom as you approach the cove on the left held a lot of fish. Also, wade out past the rockpile just straight off the ramp and fish a big crawfish colored marabou wooly bugger. I'd go auburn / brown with webby hackles in furnace or kingfisher blue. A couple pheasant rump feathers tied as claws couldn't hurt. You might hook a 5 pound smallmouth - but let him go. I feed him crayfish with my kids every summer. Keep your eyes open for big brood salmon.
Lexington Reservoir's great in rain... (yes that little puddle) wade out on the beach and fish to either edge. Rocks on right, grassy bank on left. Early-early morning. I did well with nymphs on a dry line, emerger gnats when they were boiling on top, and the rainbows were very aggresive toward black-nosed daces and smelt patterns at first light. That beach is one of the best spots to night fish on a warm night with floating line and a biot stone nymph on a floater - the fish are cruising the beach shallows where people swim. This is a put and take fishery, the fish don't holdover but it's close and entertaining.
I'd be confident in the Sperry cove section of White's... the spot was loaded with trout last weekend.
Skipping many steelhead in the rain...
In streams the levels and flotsam is the biggest concern in rain. The fish are spunky although the rain puts the dries in question. Hate to say it but most stockers aren't real smart. I like fishing streamers to weed out the aggresors, but am not ashamed of nymphing. Squanacook was at good levels and color but most have been unhappy about the cold temps keeping trout down.
Cochituate flows thru a concrete passage from one basin to another on that small road parallel to the Pike. There is parking for a few cars, the water flows from right to left looking at Natick Mall. If you can get a streamer into the outflow from the bank on the right and swing it through you should find a bunch of stockers this time of year. I worked early shift in Westboro and had many productive days there on marabou smelt in small sizes (purchased from the old orvis store in Wayland).
Scargo Pond in Dennis - you must know well. GREAT trout fishing.
In NH, the upper Souhegan is a great stream loaded w/ trout and just over the line. I'll bet the streams in the White Mountains are fishing well.
Wonder how the late spring searuns are doing? March is a good month, but this year being late...
A canoe, sinking line, streamers and nymphs on a kettle pond with plenty of raingear sounds like a nice outing to me.
I think I just talked myself into a little outing before I drive my daughter to college open house!