Past IEM Features tagged: summer
Summer is Nigh
22 May 2023 05:30 AMWith Memorial Day weekend clearly in view, the summer season is at hand. Some say summer starts with Memorial Day weekend, others say 1 June, and others say the solstice around 21 June. A data driven and backward looking approach could consider the 91 consecutive days for a given year with the warmest average temperature as the summer season. The featured chart presents the start date of each yearly period for Ames. A simple trend line is fit to the data and the dots are colored by the temperature departure from average for that given year. The simple average is indicated to be around 7 June, so perhaps we can enjoy the spring season for ten more days!
Voting:
Good: 8
Bad: 0
Abstain: 1
Tags: season summer
JJA Average Temps
02 Sep 2022 05:29 AMWith the summer months of June, July, and August (JJA) now in the books, it is a good time to review how the summer fared. The featured map presents an IEM estimate of climate district average temperature ranks for the period. A rank of 1 would indicate that 2022 was the warmest since at least 1893 and 130 the coolest. Values in Iowa are in the 50 to 70 range, so most are slightly warmer than a median rank value of 65. Looking more broadly, we don't find too much for extreme values in the corn belt with the warmest areas off to the south and west. Looking forward in time, the seasonal forecast outlooks from the Climate Prediction Center continue to advertise an above normal chance at warmer than average weather for the period with the highest chances again off to our west.
Voting:
Good: 19
Bad: 0
Tags: summer
Summer Season Precipitation
05 Aug 2022 05:30 AMPrecipitation has been difficult to come by for much of Iowa this summer. The just released US Drought Monitor update had significant deterioration, specifically over southern Iowa. Summer in Iowa tends to either feast of famine for precipitation as both extremes tend to increase their respective extremity with dry conditions limiting moisture and thus storms, with the opposite situation having the opposite effect of more storms increasing moisture and increasing future storm chances. An illustration of this feast of famine can be found with the featured chart plotting summer season (Jun-Aug) precipitation for Ames. This year continues the past three years being below average. The long term linear fit trend is upward, but the fit is not statistically strong and being pulled upward by the wet years of 1993 and 2010.
Voting:
Good: 12
Bad: 0
Abstain: 2
Tags: summer
Summer Dew Point Trend
13 Aug 2019 05:28 AMThe featured chart presents an analysis of average summer (Jun, Jul, Aug) dew point for Des Moines based on available hourly observations. A simple linear regression fit is shown for the dataset and indicates an upward trend. The color of the bars indicate if the given year is above or below the simple long term average. A majority of the recent 30 years are shown to be above average. Preliminary data for this year (not shown) has this summer coming in slightly above average as well. The near term forecast has a drop in humidity for mid-week.
Voting:
Good: 15
Bad: 0
Tags: dewpoint summer
More time for summer
11 Aug 2017 05:32 AMA few chilly evenings, preseason football, and school starting soon have many thinking thoughts of fall. If you consider the summer season to be the 91 day stretch with the warmest average temperature, there are still a few weeks left of summer! The featured chart displays the end date of the warmest 91 day period each year for Ames. A simple trend line is fitted and shows a slightly negative trend. Temperatures look to feel a bit cooler than typical for summer for the next week, but warmer temperatures are expected by late next week.
Voting:
Good: 14
Bad: 0
Tags: summer
Humid Summer
01 Sep 2016 05:34 AMThe meteorological summer season of June, July, and August are now in the books, so it is an appropriate time to review some stats. The featured chart displays an average dew point reading each summer based on the hourly observations from the Des Moines Airport weather station. This average is computed by averaging the mixing ratios and not a simple average of the dew point temperature. 2016's value is practically tied at 2nd place with 2011 at 66.1 degrees. 2010 is the highest in this chart at 67.3 degrees. This chart also nicely shows one of the main climate change trends in the state, which is for more humid summer seasons although not all recent summers have been on the high side of long term average.
Voting:
Good: 13
Bad: 0
Tags: summer dewpoint
Warmest Three Day Period
19 Jul 2016 05:28 AMThe featured chart displays the warmest three consecutive day period for Des Moines for daily high temperature each year. The top panel shows the actual three day period each year and the bottom panel presents a histogram of these periods by day of the year. July is certainly the favored month for this metric, but they have happened in the past from May to even September. It will be interesting to see if the upcoming hot weather later this week will surpass the warm stretches back in June.
Voting:
Good: 8
Bad: 0
Tags: summer
Ended Summer on Time
01 Oct 2015 05:34 AMOctober is now here and gone is most any hope for a return to summer. If you consider summer to be the warmest 91 day stretch of the year, the featured chart is for you. It displays the end date of the warmest 91 day period for each year for Des Moines. The long term average date coincides with the end date this year, 7 September.
Voting:
Good: 12
Bad: 15
Abstain: 3
Tags: summer
Start of Summer
28 May 2015 05:43 AMThe unofficial period of summer is considered to be the days between Memorial Day and Labor Day. If you consider summer to be the 91 (quarter of the year) warmest day period of the year then the featured chart shows you when this period started for each of the past years for Ames. This analysis would indicate that we have, on average, just over a week left of spring before summer starts. The near term forecast would indicate that as well with pleasant temperatures for the next week.
Voting:
Good: 15
Bad: 7
Abstain: 8
Tags: summer
End of Summer
02 Sep 2014 05:42 AMLabor Day is considered the unofficial end of summer, but does summer really end near Labor Day? If one considers the warmest 91 day stretch of the year to be summer, then this saying is a close approximation. The featured chart shows the end date of the warmest 91 day period for the areal averaged temperature for Iowa. The end date this year is shown as August 26, so we have been out of summer for a number of days now! The average end date is near 7 September. A simple linear fit is shown to this chart, the trend is the period to end sooner each yet.
Voting:
Good: 9
Bad: 6
Abstain: 3
Tags: summer
Overnight Precipitation
03 Jun 2014 05:37 AMA large complex of thunderstorms are expected to fire to our west today and bring heavy rainfall and severe weather into Iowa on Tuesday evening and night. Nighttime precipitation is a very important part of Iowa's annual total. The featured map displays an IEM computed percentage of total precipitation during June, July, and August that falls during the twelve hours between 8 PM and 8 AM local time. All things being equal, we'd expect half (50%) of the precipitation to fall over a twelve hour period (50% of the day), but it does not work out that way for much of the country. A clear maximum appears over southwestern Kansas thanks to a phenomena known as the low level jet, which drives thunderstorms during the overnight hours and helps push them west through places like Iowa. Minimums appear over the deep south and desert southwest. These locations get summertime thunderstorms driven by peak heating from the sun driving instability.
Voting:
Good: 23
Bad: 8
Abstain: 2
Tags: precip jja summer
Has summer started?
15 May 2013 05:43 AMExtremely warm air aloft was able to mix down to the surface yesterday and drove temperatures to record levels. The century mark was breached over northwestern Iowa with Sioux City topping out at 106! It certainly felt like summer. For Des Moines, the high was 94. Has summer already started? The featured chart presents the percentage of daily high temperature reports that occurred within the warmest 91 day period of the year or during meteorological summer (Jun, Jul, Aug). When Des Moines experiences a 94 degree high, ~95% of the time this day was also within the 91 warmest days of the year. So perhaps we have gone from snow to summer within two weeks.
Voting:
Good: 28
Bad: 6
Tags: summer
Warmest summer since 1988
03 Sep 2012 05:41 AMWhile Labor Day is the unofficial end of summer, the end of August is the official end of meteorological summer (the months of June, July, and August). The average temperature this year was the warmest since 1988, but only slightly warmer than last year. The featured chart presents the average summer temperature for Iowa for each year since 1893. September has gotten off to a rather warm start with highs in the 90s for most in the state.
Voting:
Good: 26
Bad: 8
Tags: 2012 summer
Dry last half of summer
26 Sep 2011 05:55 AMThe last half of summer was a dry one and according to IEM estimates of statewide averaged precipitation, the driest since 1984 for the period from 1 July to 24 September. Some rain is in the forecast today before another stretch of dry weather begins lasting into next week.
Voting:
Good: 20
Bad: 5
Tags: 2011 summer
Warm and low humidity
02 Jun 2011 05:55 AMYesterday was a very pleasant day with highs in the low 80s and comfortable humidities with dew points in the 50s. The featured chart presents the frequency of having a dew point temperature below 60 when the afternoon high temperature was above 80. You can see the frequency declines as we get deeper into summer and the humid air becomes unavoidable!
Voting:
Good: 13
Bad: 8
Tags: humidity summer
Lows above average
04 Sep 2010 06:44 AMThe featured chart presents the number of days during the meteorological summer (June - August) that either the high or low temperature were above average. The average used was the current standard climate (1971-2000). For 2010, 74 out of the 92 days were above average for low temperature which is easily the largest value on this chart for low temperature. The colors represent if the value was above 46 or below. The 1930s stand out for being warm while the 1960s for being cool.
Voting:
Good: 48
Bad: 12
Tags: 2010 summer
Stay in the 80s
09 Jul 2009 06:07 AMThe featured chart is the yearly maximum stretch of days where the high temperature was 80+ °F for Ames. So far this year, we have seen a stretch of 13 days while all of 2008 only experienced an 11 day period. In general, the longest stretches were prior to the 1960s with 1936 having a 70 day period! Our forecast has highs in the 80s, but barely 80 for the weekend.
Voting:
Good: 18
Bad: 1
Tags: summer
A warm feature
30 Jan 2009 06:15 AMMaybe a feature about summer would help us to think warm thoughts and hopefully look forward to summer! The featured chart displays the number of days between the first and last occurance of 90+ degree temperature in Iowa. 2008 comes in as the second shortest season with only 100 days. Again, 1993 shows up prominently with 2008 in a chart. Of course, 90 degree temperatures are not in the immediate forecast, but let us hope for any number above freezing!
Voting:
Good: 32
Bad: 17
Tags: 2008 summer
Muggy weather still possible
13 Aug 2008 06:50 AMThe featured chart is a histogram of the percentage of years that a 75+ degree dew point was observed per day since 1973. The frequency is roughly 1 in every 5 years during the summer with July having the most days.
Voting:
Good: 17
Bad: 11
Tags: summer dewpoint