1) Heat slows down bird activity (of all kinds). Watch for hummers early and late in the day when temps moderate. Consider adding a water mister for a nice water source for them.
2) Heat also breaks down nectar. Clean your feeders and replace nectar more often in hot weather.
3) Hummingbird natural food sources - insects and natural nectar - are extremely plentiful. Remember that our feeders are just a fast-food supplement for these guys!
4) Moms are busy tending to activities at the nest. She's a busy single mom spending many hours on the nest incubating eggs. When the eggs hatch, she is very busy searching for high protein food sources (not nectar) to bring back to the nestlings.
Don't worry - you'll see them all soon. Until then, try out some or all of these tips to increase your hummingbird enjoyment during these hot days of summer!