I’ve been playing the same chanter reed since 2009. I’ve noticed that towards the end of the Canadian winter (April), my reed tends to lose a little of it’s tone, particularly in the lower hand first octave. The bottom D is weak, and the hard D is unimpressive. In the past, I’ve nearly given up on the reed and, I’ve even made replacement reeds, but when May arrives, it bounces back miraculously. I’m going through this right now. It’s an exercise in patience not trying to tweek the reed but I know that if I leave it alone, it’ll be back to itself in a few weeks.
The same thing happens to me every year with the vicissitudes of the Eastern Canadian weather. Some winters there are periods I can’t play at all, although I have a David Daye penny chanter with one of his reeds that he treats with some kind of oil I think that does tolerate the extremes more successfully.
Mike
The best investment I’ve ever made was a cheap battery operated humidity meter. It is probably nothing like accurate in the absolute sense, but it is consistent to itself. Every practice session I note the reading when I pick up the chanter, and again after about ten minutes of playing time. My reed tracks right along in a consistent fashion. This lends a certain amount of sanity to my piping world. When it goes ‘out of bounds’ I know to break out my dry reed, or even put on the electric tea-kettle in the room.
Bob
I think that our life will be changed when we’ll be able to make adjustable bridles, that can follow the cane shrinkage or swelling, and keep the same pressure LATERALLY all along the year.
I’m seriously thinking about it,but it appear to be sort of watchmaking job…and i’ve a lot to do before I can spend time on that!
I recently saw the clip with a 3-D printed chanter. It’s probably only a matter of time before synethic chanter reeds are available, and then all this fun will be over!
Légère Reeds. They say they are working on ‘bagpipe’ reeds. GHB I imagine. They’ve never responded to me about Uilleann reeds.
They say, according to their newsletter, that they are about to be able to offer consistent Oboe and Bassoon reeds. They have a whiz-bang material that mimics the elasticity and stress modulus of cane coupled to a 3-D laser cutting process. Nowhere cheap, but getting good reviews from select professional Bassoonists.
Oh, well, after NPU logs their 1 millionth member we may become an economic market. . . . 
Bob
This, and a decent (not super cheap) room humidifier. As long as I keep my practice room over 50% humidity, I never have to touch my reeds. Previous to the humidifier, I was having to adjust the bridles every 2-3 months.
PJ’s experience EXACTLY mirrors mine! It’s like that every year about this time. I don’t humidify per se -all winter- so one would think that not much would change until the blessed arrival of spring’s damp. Yet, come April, my reed loses some character, only to get it back in May. As if it just gets tired of this whole winter-thing. I know how you feel, Ol’ Iron Lips (that’s my reed, not PJ).
From America’s Deep North,
Hi PJ,my name is Jay and im new here but have been making pipes/reeds for 16yrs (quietly,word of mouth other musician’s ect…web site will be up and running soon) I have had the same problem with reeds aand different climates and seasons ect…after reading all the other poata to your problem there seems like a few good ideas there,have you tried to open your reed by gently squeezing the bridle slightly with pliers therefore making the internal volume the same when its played in good conditions?
You can (with your fingers) slide the bridal on the reed UP …this has a similar effect too.
All the best
Jay
PJ - this is 2016! I reckon your set is older than 8 months - which in turn means that your warranty is outdated: You have to kick the whole thing into the bin and buy a new set. 
On my chanters (by three different makers), doing that will throw some notes out of tune. I have found it much better to squeeze the bridle gently but leave it in place to make adjustments.
I don’t believe the OP is about “how to tweak a reed”. It’s more an observation on the incongruous change that happens well at the end of a long winter/beginning of spring. Seems like the reed would sadden long before March/April. But it takes a downturn right before spring hits.
In Southern California, we switch to a summer reed that has up to 10% Ethanol added…
Possibly it isn’t the reed waiting until April. Maybe in April the sudden spike in humidity affects a change in the reed, which takes the reed a while to adjust to the new quality of the air? Once the reed is acclimated to the new atmosphere it sounds normal, but it’s the transition that throws it off.
I have played reeds made by various pipemakers and reedmakers through out the years and seasons with attendant humidity fluctuations.
David Daye’s reeds have proven the most tolerant to low humidity in particular, by a long shot. I believe that he soaks his reeds in some sort of oil, which would/could account for this. Does anyone know what kind of oil/soaking process he uses and whether he does this with the cane before the reed is made or if it is something you can do post-manufacture?
I can recall years ago being in a class in the dead of winter at the Chris Langan weekend in Toronto. I was able to play my David Daye set whilst the rest of the class was struggling in sub 30 % humidity to eke out a tune.
Mike
This is to An …yes moving a bridal up and down can have an effect on some reeds esspecially the ones that have a wider bridal and its position is a fair bit away from the base of the winding on the reed its self.thats why i make my reeds with a lower and thinner bridal out of slightly thicker copper or brass.that way you an open and close the reed evenly with out it affecting the intonation of the chanter.
I also use shelac lightly on the inside of the reed.i do a double application using sanding cylinders and very fine sandpaper…shelac is quite flexable and weather resistant so it handles the weather conditions quite well.
Anyway thats just me hope you find a solution soon☺
Happy piping