If you’re planning a trip to one of the most breathtaking wonders of the natural world, you want to be sure that the weather isn’t going to spoil your enjoyment of the great outdoors. Peak visiting season to Niagara Falls is May to September—and for good reason: the days are long and warm, typically in the low 20s Celsius (70s to 80s Fahrenheit), the nights are comfortable with lows around 17 ° C (63 ° F), and all of the most popular tourist attractions, like Maid of the Mist
boat tours (which operates April to October) are open.
If you want to experience Niagara Falls in all its glory, you’re going to want to be there at a time where you can be free to wander (unfrozen) around, soaking in the majesty of nature. If you come in the summertime, you’ll be able to camp and hike on dry trails for hours, even if you do have to battle the crowds a bit more than in the off season.
That said, the off season doesn’t turn Niagara into a ghost town; the Winter Festival of Lights (early November to early January) has millions of lights throughout Queen Victoria Park, and well as concerts and other events, there are still a number of museums and cultural sites open year round (and of course the Falls itself can’t exactly shut down), but snowfall into mid-April and sometimes bitterly cold temperatures do put a damper on most outdoor activities.
The October shoulder season can be very nice as well. Many of the hotels in the prime tourist areas offer great packages as the summer high season ends and the weather is still moderately nice ( although you will want to bring a sweater for the cooler evening temperatures).