The June heat wave we had up my way has done wonders for my chili peppers. My luck is frequently hit or miss each summer because chilis love heat, and I can't always give it to them. They have leafed up really well, even the superhots and the plants that didn't handle transplanting too well. Hopefully we get another run or two of hot weather once they start setting fruit, and I might be making hot sauce by labor day.
I am surprised at how well chilis do up here. We find planting them in containers works best. As I recall we mostly harvest them in late September (but using green ones all summer) and make plenty of fermented hot sauce to last the year and give away. Mostly jalapenos, habeneros, and thai peppers for sauce. We grow the hot cherry peppers mostly to stuff with cheese and roast. yum.
Jalapeños always do great for me. It's the superhots (1+ million scoville) like ghost peppers and reapers that need 90 degrees plus days to really thrive. A cold, wet summer almost always leads to disappointing yields for me.
Also, shout out to chiliplants.com while I'm at it. I grow mostly varieties that are hard to find in a nursery, so I have to start them from seed. I never got around to starting seeds this spring, but I came across this website and decided to order a bunch of plants from them. Not only did they have a huge selection, but the plants arrived in good shape, and they're all thriving after being transplanted into containers. They're pricier than starting from seed, but I wouldn't hesitate to order from them again if I needed to.