(Fritz Hahn/The Washington Post)

It’s All-Star Weekend in Washington, and baseball fans are overrunning the capital. A mini-heatwave is also moving in, with temperatures in the 90s and a triple-digit heat index through Tuesday.

The big event isn’t until Tuesday evening, but there are several events — outdoor and indoor — leading up to the All-Star Game at Nationals Park.

For the outdoor fun, we suggest sunglasses, light-colored clothing and sunblock. An umbrella will go even farther to keep you cool and keep the sun off your skin.

And of course, you’re going to need plenty of water. Sealed water bottles and empty personal bottles are typically allowed through the gates at Nationals Park, as long as you’re not packing too many of them. (Pro tip: You can usually bring in outside food, too, as long as it’s in clear containers like freezer bags or clear, soft plastic containers. Hard plastic is technically not allowed in the park. Your mileage may vary on this one.)

Below you’ll find a detailed forecast for the outdoor events leading up to the All-Star Game:

  • Armed Services Classic
  • MLB All-Star 5k
  • All-Star Sunday
  • MLB All-Star Game

Armed Services Classic

When: Friday, 7 p.m.

Where: Nationals Park

When gates open at 5 p.m., the temperature will be close to the hottest of the day — around 86 or 87 degrees. There may be a few clouds in the sky, but the sun will be beating down until it gets low around 7 p.m. Humidity isn’t terrible today, with dew points only in the upper 50s. That should make it a little more comfortable than it otherwise would be in mid-July in Washington. There’s no chance of rain tonight, so the game itself is in the clear.

MLB All-Star 5K

When: Saturday, 8 a.m.

Where: Yards Park, at First and M streets SE

It’s relatively cool Saturday morning as runners stretch and line up for the race. Expect temperatures in the upper 60s at 6 a.m., climbing to the low 70s at the race’s start. By noon, the mild morning is a distant memory as temperatures reach the upper 80s on their way to a high of 90 later in the afternoon. Fortunately, humidity is low. Just remember to wear sunblock.

All-Star Sunday

When: Sunday, All-Star Futures Game begins at 4 p.m., followed by the Legends and Celebrity Softball Game

Where: Nationals Park

The heat really starts to crank up on Sunday. High temperatures will be in the low 90s and they’ll max out right about the time gates open for the event. The dew point will be in the upper 60s, so humidity is much higher than previous days. There’s some relief in the form of clouds, which should be numerous by the evening. There’s also a slight chance of a passing shower or thundershower, but it doesn’t look serious enough to cancel or delay events.

Home Run Derby

When: Monday, 8 p.m. (gates open at 5 p.m.)

Where: Nationals Park

Oh man, it’s hot. And there’s a chance of thunderstorms, too, which may actually cool things off but certainly aren’t going to be good for the derby itself. Temperatures are going to be in the mid-90s when gates open, and combined with high humidity, the heat index is likely in the triple digits. The highest chance of storms or showers is between 2 and 6 p.m., so Nationals Park may stay dry through the evening. By 8 p.m., the temperature drops to the upper 80s, which is still pretty hot given the humidity. A light breeze might help cool things off. At 10 p.m., temperatures are in the low 80s.

MLB All-Star Game

When: Tuesday, 8 p.m. (gates open at 4:30 p.m.)

Where: Nationals Park

It’s going to be hot, but the biggest risk to the All-Star Game is the 50 percent chance of storms through the day. At some point between 1 and 11 p.m., Nationals Park will most likely get some rain, if not a full-on thunderstorm. The question is whether it’s enough rain to delay or even cancel the game. Temperatures reach the low 90s in the early afternoon, then cool off as showers and storms move through. Humidity stays very high, with dew points in the low 70s. The cold front approaching from the northwest doesn’t arrive until well after the game, which means Washington will be in the thick of hot, muggy July weather through the evening.