Overall Las Vegas has mild weather and that's one reason a lot of people moved to Vegas. We have more sunny days than most other cities, no tornadoes, and obviously no hurricanes. However, the mountains around Las Vegas have their own weather. We will look at these factors so you can dress appropriately when you go hiking. We will also look at the best weather resources on the internet and you will read some interesting and surprising weather facts.
I use three different internet sites to check the forecast:
Weather.com - good for a quick overview, especially the next 10 days. I like the layout of their page the best.
National Weather Service - you can pinpoint an exact location with their interactive map. For example, you can check the temperature and forecast for the summit of Mummy Mtn.
Weather Underground - has the forecast for Red Rock Canyon, including wind speed, chance of rain, and humidity. (note: the link I provided is for Red Rock Canyon. You can change it to another location.)
Weather Facts for Vegas and the Mountains:
Usually the forecast does not vary too much within 48 hours. Meaning if there's a 50% chance of rain forecast on Wednesday for Friday, it probably will not change. However predicting the weather is not an exact science. As an example as I write this on Tuesday there was an 80% chance of rain on Friday. It dropped to 20% Wednesday and now (Thursday) it's went up to 40%. When you see this, all bets are off.
For every 1,000 feet you ascend, the temperature drops four degrees. This is very important as you will read later in the article.
It does not rain as much as the predictions.
The mountains can create their own weather. This is more true of Mt. Charleston than Red Rock.
While lightening is a real concern in Mt. Charleston, it's uncommon in Red Rock Canyon.
The Monsoon season is characterized by violent thunderstorms that occur in the mountains. Around Las Vegas we are talking about Mt. Charleston. The Monsoon season normally does not start until mid to late July and last through August.
The hottest month of the year is July, not August. (Average: 104 degrees)
The coldest month is December (Average: 57 degrees)
Coldest day ever recorded: 8 degrees Jan 13, 1963
Hottest day ever recorded: 117 degrees July 24th, 1942 and July 19th, 2005
The average temperature in September is mid 90's.
Annual rainfall for Las Vegas: 4.19 inches per year.
Days per year with precipitation: 21
Weather and Hiking
Here are some rules I follow:
How can you hike in Red Rock when the forecast is 110 degrees?
It will not be 110 degrees in Red Rock. Why? First, that 110 degrees is for Las Vegas (elevation 2,200 feet) at 5 pm. If you start hiking at 6 am in Red Rock it will not be close to 110 degrees. It's the coolest in the morning. Second, the temperature drops four degrees for every 1,000 gain in elevation. Red Rock starts around 4,000 feet, so it's eight degrees cooler. Hike to a 6,000+ foot peak and it's 16 degrees cooler than Vegas.
Example: You are at a 6,000 foot peak at noon. It's 100 degrees in Vegas. You are roughly 4000 feet above Vegas. 4 x 4 = 16 degrees cooler, meaning it's only 84 degrees at the peak. That sounds a lot better than 110 degrees.
Another tip is to hike routes that have a lot of shade. Two that come to mind are Oak Creek Overlook and Kraft Mtn., the West Face route. This latter route is entirely in the shade if you start around 6 am.
Hope this helps you have a better hike. If you have some weather tips, post them.
Branch Whitney is the author of Hiking Las Vegas and creator of the 52 Peak Club where members hike to the best 52 Peaks around Las Vegas, NV