Grand Canyon Rafting Weather

Grand Canyon Weather Overview 

There is not a bad time of year to raft the Grand Canyon, only poor clothing choices. While we wish we could give you a finite answer to the “best time to raft Grand Canyon” question based on reviews from past clients, since 1987 we’ve found that the answer to this question varies from person to person. Below is a break down of the variations in the canyon for each month.

March-April

This is the month most rafting outfitters plan their hiking intensive trips because the cooler air temperatures allow the guides to share some spectacular, longer, dryer side canyon hikes that aren’t possible during the hotter summer months. What makes the hikes even more impressive during this time of year is the blooming wildflowers. However, the cooler air temperatures and the potential for a late winter storm require extra preparation for the whitewater portion of the river trip which means dressing in layers of warm quick drying clothing many times including a wool cap and socks with your outer most layer being a good waterproof two piece rain suit.

A Note About Spring Time Rafting

Spring is a beautiful time visit Arizona and especially to raft the Grand Canyon! In the lower elevations at the bottom of the canyon the wildflowers may be blooming and all the foliage is green as opposed to being slightly crispy during the summer months.

However, the weather can vary with late winter storms rolling through the area sometimes even up to the last week in May. At lower elevations, a winter storm can manifest as rain and at higher elevations such as the South Rim of the Grand Canyon or Flagstaff it can mean snow!

While the average daytime temperature at the bottom of the Grand Canyon is about 70 degrees with possible highs in the 80’s, it will only feel this warm when you are standing in direct sunlight and away from the river. The river water is about 50 to 55 degrees at this point in the canyon and no matter where you sit in the raft, you will be getting soaked from head to toe. The ambient air temperature is always 10 degrees cooler when you’re on or near the river and it can feel an additional 10 to 15 degrees cooler when you’re in the shade. If a late winter storm rolls through or the wind picks up, the temperature can drop by an additional 10 to 20 degrees.

Dressing for Spring Time  

The key to having fun while rafting in the spring is staying warm and dry, which means a good waterproof, two piece rain suit is an absolute must! You will want to dress in layers of warm quick drying clothing such as SmartWool, fleece, and polypropylene. Your base layer can be shorts and a t-shirt, with your next layer being mid-weight fleece pants and jacket, with your outermost layer being your rain gear. 

May

Early May is still a good time to raft if you’re looking to avoid the heat and there may still be some wildflowers in bloom. It is still possible for late winter storms to occur until mid-May and usually by the last week in May the weather will level out. 

June

Historically speaking, June consists of clear skies and sunny days with average day time temperatures of 95 degrees with highs in the 100’s. This is one of the best rafting months for clear water which means the main river is going to be a deep emerald green with some of the side canyon streams most notably the Little Colorado and Havasu Canyon being a brilliant turquoise blue.  

July and August 

It is arguable as to whether these are the hottest months to raft in the Grand Canyon because our monsoons are in full swing during this time of the year.  The average daytime temperature is in the 100’s with highs around 115; however, the cloud cover provided by the monsoon storms does cool things off and if it does rain it can drop the temperature by 20 to 30 degrees depending upon the severity of the storm. 

Our monsoons usually manifest themselves with sunny mornings and cloud cover rolls in around lunchtime then if it does rain where you are it is an intense but brief storm before clearing up in time for dinner. Of course, this is weather, so there can be some days that can be overcast with intermittent showers and it can also sometimes rain during the night. In spite of the water being muddy due to the rains, this is a popular time for photographers to visit the canyon because the monsoon storms create unique lighting opportunities and there is nothing more spectacular than a rainstorm in the Grand Canyon.  

September 

By National Park decree the last motorized rafting trip through the inner gorge depart from Lee’s Ferry on September 15 every year after that there are only non-motorized multi-day trips available which means you’d have to dedicate at least six days to rafting.   

September has temperatures that are similar to June and is generally pretty stable month weather wise; however, because it’s fall 95 degrees feels cooler in September than it does in June. This is effect is very noticeable in that when you’re standing in the sun, you’ll want to be wearing shorts and a t-shirt, but as soon as you step into the shade you’ll want to put on some warmer layers.  This is also a good time to raft for clear water.  

October

There are even fewer departure dates in October than September because there is less daylight the trips have to be longer.  Trips through the inner gorge (that pass through Phantom Ranch) are strictly non-motorized during this time of the year; however, those who cannot dedicate at least seven days, the one day motorized whitewater rafting trip in the lower gorge (starting at Diamond Creek – river mile 225) runs through October 31 every year.   

The average daytime temperature is about 80 degrees with highs in the low 90’s – the temperature difference between standing in the sun and standing in the shade during this time of the year is even more extreme in October than it is in September. Also, the later you raft in October the more important it is to be properly dressed in case of early winter storms. 

Disclaimer: When you’re looking at the temperatures below, please keep in mind that Grand Canyon is a place of extremes and the Colorado River starts at about 48 degrees Fahrenheit at Lee’s Ferry (river mile 0) and only warms up one degree every 15 to 18 miles you go down river – even in August when the ambient air temperature is 100 to 115! It is always 10 degrees cooler whenever you are on or near the water. If a storm rolls through the area and/or the wind picks up, it can drop the ambient air temperature by another 10 to 20 degrees in a matter of minutes.