Wisconsin weather and pumpkins; too soon to put them outside?

MILWAUKEE - Fall is here and that means decorating, especially with pumpkins. But is it too early to purchase pumpkins and put them outside? Weather has a big impact on whether pumpkins will last until Halloween or even Thanksgiving. 

Pumpkin facts

By the numbers:

Pumpkins are about 90% water, which is why they can be so heavy. States from the Midwest into portions of the northeast produce most of the pumpkins in the U.S. According to the U.S. Department of Agriculture, in 2022, Illinois had 524 pumpkin farms and Wisconsin had 962 pumpkin farms. 

Illinois surpasses all other states when it comes to producing pumpkins – about 70 to 80%. But only 31.5% of pumpkins in Illinois are sold for decorative purposes, with 68.5% used for processing such as canning and puréeing.

How weather affects picked pumpkins

Dig deeper:

The University of Illinois Extension program says that pumpkins are very tender vegetables that are greatly impacted by extreme "hot" and "cold" temperatures in fall. They also are impacted by rain and morning dew, but the impacts will be larger depending on whether your pumpkin is carved.

Uncarved Pumpkins

Uncarved pumpkins can last several months outside, especially when cooler temperatures are around.

• Too cold, the water inside pumpkins can freeze and expand. When temperatures warm up again, it thaws and the inside becomes mushy, causing the rotting process to begin.
• Too warm outside, this can dehydrate the pumpkins faster, allowing them to rot more quickly.
• Too much moisture from rain and/or dew on surfaces. This can cause the pumpkin to rot from the bottom as mold can develop if it is sitting on a wet surface, including a porch.

Carved Pumpkins

Carved pumpkins can typically last a week, or maybe two if you’re lucky. 

• Colder climates help prevent them from rotting quicker.
• Mild or warmer temperatures, carved pumpkins lose moisture at a faster rate, causing them to become softer and oxidize quicker. This is similar if you cut an apple and leave it on the counter and it turns brown.
• Putting a real candle in a carved pumpkin also makes it warmer inside, which increases the drying and rotting process, leading to the pumpkin shriveling up and molding in a flash.

Make pumpkins last longer

What you can do:

Here are some tips to make your pumpkins last longer.

• Keep them in a cool area and avoid placing them in direct sunlight.
• Bring pumpkins inside during very warm days and very cold nights.
• Keep the pumpkin off of damp surfaces and dry it if it is sitting on wet ground.
• Use a battery light in a carved pumpkin rather than a real candle to preserve it longer.

October weather forecast

Big picture view:

So far, fall has been mild with temperatures gradually cooling through September. The Climate Prediction Center has a probability temperature outlook for October that forecasts Wisconsin to have the potential for slightly warmer than average temperatures with well above average conditions contained near the Gulf. While slightly warmer than average is expected for the month, there can still be colder than average days at times. 

The Climate Prediction Center has a probability precipitation outlook for October that forecasts Wisconsin to have equal chances for above or below average precipitation. There are no major indicators that the Milwaukee area is favored for well above average or well below average precipitation amounts. 

Based on this, the weather could be more favorable for pumpkins to be outside. However, it will be important to still pay attention to the daily forecast where conditions may warrant you to take them inside for a day or two.