BILLINGS- This Saturday at 7:54 p.m. marks the official end of the summer season. With that in mind, it seems fitting to look back on summer 2018 before sweater sets in.
I’ve wrapped up some numbers showing the highs and lows of the past three months of summer.
This summer, we saw our share of weather-related ups and downs. Especially in August, where we saw 100-degree temperatures in August for the first time since 2011, as well as sub-60-degree temperatures a week later.
The numbers shake out like this: We had 19 days where temperatures topped 90 degrees, the lowest total in the last three summers. And we had three days where the temperature topped 100 degrees, the highest total in the last three years.
So far, we have had eight days where the temperature failed to reach 70 degrees. If the forecast stands for this week, we should add another three or four days to that total.
After a very rainy spring, things dried out over the summer months. And with no measurable precipitation in September, we are roughly four-tenths of an inch short of the average precipitation for the summer months. Again, the forecast for the rest of this week will likely change those numbers, as we are expecting scattered rain showers late in the day on Wednesday and into Thursday.
To give you a little context as to how these numbers characterize our summer as a whole, here is how this year’s figures compare to the prior two summer seasons.
| Year | >90° Days | >100° Days | <70° Days | Rainfall (departure from average) |
| 2018 | 19 | 3 | 8 | -0.4” |
| 2017 | 42 | 2 | 8 | -2.35” |
| 2016 | 33 | 0 | 11 | -0.13” |
The summer of 2017 jumps out as both very hot and dry, with more than double the number of 90-degree days we had this year and a rainfall shortage of more than two inches compared to historical averages.
The summer of 2016 had more hot days and also more cool days than this summer, but even in a year of temperature swings, the 100-degree plateau was never eclipsed.
If you’re like me, you see three very different summers with a high degree of variation in the weather patterns within each season. Overall, it’s a set of numbers that makes it hard to make sweeping generalizations and reinforces the point that anything can happen when it comes to Montana weather.
The notion that anything can happen goes hand in hand with a warming global climate, and with that, I will leave you with my plug about the effects of a warming climate on weather patterns:
Temperature and precipitation extremes are symptoms of a warming climate and 40-degree temperature swings like the one we witnessed over the course of a week or so this past August is a perfect example of the type of instability a warming climate begets. If the global pattern continues on its current course, we will likely see an increase in extreme weather conditions.
While this three-year sample size is too small to base these types of claims on alone, this data does fit into trends established by climate scientists.
If you are interested in learning more about why this is the case you can check out the following links. The first is the NASA page on climate change and its effects. For more in-depth reading, the second link is to the fourth National Climate Assessment, published in 2017.
