I never quite grew out of my Jurassic Park era. But let's be honest, did any of us really? Now that I'm an adult who can plan my own vacations, it has occurred to me that I can go on my own paleontology adventure.

But weather is definitely something to consider, especially since so many dinosaur sites in the U.S. are in desert climates.

In general, two time frames are your best bets if you want to hit up any of these sites (especially if you want to do a multi-location road trip). 

• Late May to early June: This is the best option for most parks, as most places are open, temperatures are still warming up and summer crowds haven’t hit their peak.
• Mid-September to early October: This is outside the “summer break” window for schools, which means the crowds will be thinning out. Temperatures are also cooling off, and some areas in the northern U.S. might be breaking into fall foliage.

But let’s dig a little deeper and get site-specific, shall we?

Dinosaur National Monument (Utah/Colorado)

Dinosaur National Monument is one of the most iconic dinosaur sites in the U.S., and it has two windows for peak visiting opportunity. Late April to May and September to October both offer the temperature sweet spot, with highs in the 60s to low 80s.

The middle of summer is more likely to see extreme heat, and there’s no shade at the quarry. Some of the trails and roads are closed for parts of the park in winter, and while the Quarry Visitor Center is open year-round, the Canyon Visitor Center closes for the winter (typically from mid-to-late October to mid-to-late May). 

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The dinosaur fossil sites are all found on the Utah side of the park, though the canyons on the Montana side are definitely worth visiting as well.

• When to go: late April to May and September to October
• Can you dig up fossils? No

Dinosaur Ridge (Colorado)

If you want to see dinosaur fossils still in the rock at Dinosaur Ridge, there are two paved, outdoor trails: the Dinosaur Ridge Trail and the Triceratops Trail. Similar to Dinosaur National Monument, the best time of year to visit Dinosaur Ridge is not the middle of summer.

Spring and fall both offer cooler temperatures, staying in the 60s and 70s, which is ideal for the outdoor walking tour. Bus tours are offered in the winter, but you have to pay, while Dinosaur Ridge Trail is free to pedestrians and bicycles. 

• When to go: May to June or September to October
• Can you dig up fossils? No

Dinosaur Valley State Park (Texas)

Dinosaur Valley State Park is a tricky one, because while the summer heat and sun are brutal, you need the Paluxy River to run low in order to see the fossils of dinosaur tracks along the river bed. Dry summers in Central Texas cause the river levels to fall, uncovering the tracks. 

Pack a lot of water, though, because high temperatures in Glen Rose, Texas, during the summer months average in the upper 80s to mid-90s. The later you wait in the year, the cooler it is, so check the park’s social media pages for updates on whether you can see the tracks.

• When to go: late August through September
• Can you dig up fossils? No

Cleveland-Lloyd Dinosaur Quarry (Utah)

Part of the Jurassic National Monument, this is another site that you should avoid in peak summer, as temperatures in June, July and August have average highs in the 80s to low 90s, often reaching the upper 90s to triple digits.

Heads up, though - this site is only open Thursday through Sunday, so don’t try to plan a trip on Monday, Tuesday or Wednesday.

As of summer 2026, the Cleveland-Lloyd Dinosaur Quarry dig site is closed for construction, but the Jurassic National Monument and its hiking trails are still open.

• When to go: April to May and September to October
• Can you dig up fossils? No

Wyoming Dinosaur Center (Wyoming)

While the Wyoming Dinosaur Center museum is open year-round, the “dig for a day” program only runs from mid-May through early September. This is another site in the open sun with no shade, so the sun will be brutal, and temperatures often reach the 90s or even 100s in the peak of summer.

If weather conditions are unsafe, your dig will be cancelled for a full refund or rescheduled.

Going at the start or end of the dig season might be more crowded, but temperatures are more likely to be comfortable in the upper 70s or low 80s.

• When to go: early-to-mid-June or early September
• Can you dig up fossils? Yes, but you don’t get to keep anything you find

Hell Creek Formation (Montana/North Dakota/South Dakota/Wyoming)

The Hell Creek Formation (a “formation” is a section or region of rock with unique characteristics that is distinct from the rock around it) digging season typically lasts from late May through early September, to avoid harsh winters and soggy, muddy springs. 

Different companies and groups offer tours, and while they typically stick to the same season, there are minor differences. The Burpee Museum of Natural History, for example, doesn’t offer any digs in July.

• When to go: June to September
• Can you dig up fossils? It depends on where you go and what company you book with. 

Sara Tonks is a content meteorologist with weather.com and has a bachelor’s and a master’s degree from Georgia Tech in Earth and Atmospheric Sciences along with a master’s degree from Unity Environmental University in Marine Science.