Extreme northeastern Iowa got clipped by a rather intense band of snowfall on Saturday. A few reports of six inches or more were found within Iowa and amounts approaching 10 inches just across the border into Minnesota. NWS La Crosse has created a nice summary of this event and explains the meteorology behind why it happened. For today, it will be far southwestern Iowa's turn to get clipped by a winter storm that will mostly stay to the south of Iowa. With it now being the first of March, it is not clear if these two storms constitute March "coming in like a lion or lamb", but it could certainly be a lot worst and even a lot better than the weather for today.

A few weeks ago, a similar map was featured showing how warm mid December through the first week of January had been for much of the contiguous US. So with the meteorological winter months of December through February now complete, today's featured map looks into how warm this winter season was. The map plots average temperature ranks since 1893 with a value of one representing the warmest over that period. There are plenty of ones to be seen over the western half of the US. Iowa is somewhat stuck in the middle, but values shown are above average.

Yesterday, the Storm Prediction Center issued their Day 4 convective outlook and covered much of Iowa with a 15% probability of a severe storm within 25 miles of a given point within the outlook area. It is certainly early in the season for such a risk to include Iowa at four days out as shown by the featured chart presenting the period between the first such risk for Iowa and last risk by year. Only 2022 had an earlier such risk, by one day for 5 March. Unfortunately, you may recall the horrific weather that day with the Winterset EF4 Tornado being the most significant. At the moment, the main tornado threat appears to stay south of Iowa.

The US Drought Monitor will be released later this morning and will likely show continued degradation of analyzed drought over Iowa. The current drought got started late during the 2025 growing season and took a bite out of what should have been exceptional crop yields. The situation has not improved much since and as we quickly approach the 2026 growing season, the impacts of recent dryness are being to be felt. The featured map presents percent of average precipitation totals from IEM tracked long term climate sites in Iowa since the start of August. A number of locations over southeastern Iowa are shown below 50% of average over this period. Hopefully a rainfall event today into Friday will bring much needed precipitation, but some parts of the state will miss out and it will be a number of days before the next significant rainfall arrives.

Thunderstorms rolled into Iowa late Thursday night and will abound today bringing much needed rainfall to the state. Having such storms during the first week of March is nothing too exceptional as shown by the featured chart. The chart presents a heatmap of Des Moines airport weather reports of thunder by week of the year and by hour of the day. The side bar charts present the histograms for each. The chart shows an increase in such activity starting about mid February and roughly increasing each week until peaking in mid June. The chart nicely shows how most of the thunder reports are during the night time hours for central Iowa as activity is often driven by the "low level jet" persisting thunderstorm complexes that develop over the plains and then move east overnight. The early spring and late fall activity shows less of a strong overnight signal as these time periods are more dominated by larger scale low pressure systems that impact the state and more tied to daylight heating driving thunderstorm activity.

The increase in humidity on Friday was remarkable with practically the entire state reaching a dew point temperature of at least 50°F and a considerable portion of the state reaching at least 60°F by late afternoon and into the evening. All of this moisture helped to fuel abundant showers and thunderstorms which brought much needed rainfall to the state. The dew point readings on Friday were at the extreme end of what is possible for this time of year. The featured chart presents the maximum reported dew point by hour for Des Moines over the inclusive 1 January through 6 March period. The plot shows thirteen hours during yesterday with the reported dew point either tied or setting an unofficial hourly record. The reported 61°F dew point at 9 PM also appears to be the overall maximum for any hour during this selected period of days.

The spectacular weather on Sunday continued into Monday with record high temperatures set at a number of locations across Iowa and beyond. The calendar says we are still within the second week of March, so there is plenty of time yet for the chance of winter-like weather. The featured chart looks into an aspect of that by plotting the last cold season date of at least an inch of snow reported for Des Moines. The yearly value is plotted along with a line until the date when snow cover was no longer reported (~ how long the snow stuck around). This combination is colorized by the number of days with red values indicating the shortest duration. The left panel black line plots the accumulated frequency of the last date. The 10 March value is somwhere just below 50%, so over half of the previous years on record reported at least a single one inch snowfall event or larger after 10 March. The right hand plot presents the date by year with two trend lines shown. A number of recent years have seen such snows into mid April and even early May, but these late season events struggle to stick around long as ever warming soils, lengthening days, and increased solar inputs act to quickly melt the snow away.

A significant severe weather event developed on Tuesday from northern Illinois/Indiana back southwest into Texas. The rough weather clipped southeastern Iowa as well with powerful storms developing during the late afternoon hours along and near a very strong surface warm front. The featured screenshot is from the ISU Soil Moisture Network homepage showing 3:30 PM air temperatures over southeastern Iowa on Tuesday. The 81.5°F plotted was near West Point and the 59.4°F was just over 30 miles away to the north near Crawfordsville. This temperature contrast made for a remarkable warm front due to the large temperature change over a very short distance. Strong warm fronts like these are typically trouble for severe weather as storms are focused along the boundary and the boundary helps to provide spin to the storms to produce large hail and even tornadoes.

After severe storms on Tuesday over southeastern Iowa, the backside of the storm system brought a small taste of winter with a brief coating of snow over most of the rest of the state. While not much for a winter storm, there was an isolated two inch snowfall report, so that arbitrary threshold triggers an IEM map with a crude accounting of available NWS and CoCoRaHS snowfall reports. This snow almost immediately melted, so proper measurement and reporting was difficult. The map shows a couple of areas of the state with over an inch of snow from the event. We are not done with winter yet as more snow is in the forecast.

There are many different aridity indices attempting to express how anomalous precipitation and temperatures are. One such index formulation is the subject of today's IEM daily feature. This index is computed by taking the standardized departure of average high temperature and subtracting the standardized precipitation departure over trailing 180 day windows of time. The standardization is done by dividing the actual departure by the standard deviation value, which creates a unit-less value that be used to lump the temperature and precipitation values together. Of course, no index is perfect, but some are useful. Anyway, values that are more positive are indicative of periods of water availability stress (warmer air temperatures and low precipitation totals). The trick is to realize that the precipitation departure is being subtracted in the equation, so negative precipitation departures increase the index value. What is interesting about the plot showing data for Ames since 2012 is that current values are some of the most positive shown and starting to be comparable to those during the drought of 2012. The drought situation is not urgent yet as the growing season has yet to start, but increases in precipitation would certainly help to improve drought indices like the one shown here.

Nothing like a good ole fashioned plains blizzard to remind everyone that we are not done with winter yet. The featured map attempts to analyze available snowfall reports from the NWS and CoCoRaHS, but will need updated later this Monday after more reports are received. Most of this now fell sideways and over along duration, which makes for difficult measurement and reporting. For Iowa, the highest snowfall totals were isolated to far eastern and northern Iowa. The lesser totals over the rest of the state still had a significant impact as strong winds and frigid temperatures have iced up practically all the roads for the state. The current map does indicate some areas without measurable snowfall, but more reports received later today will likely fill those in with at least measurable totals. Much warmer weather will quickly return this week.

During our recent storm, 93 of Iowa's 99 counties were simultaneously under a Blizzard Warning. Is it possible to assess how much of that area experienced blizzard conditions and thus verifying the warning? A blizzard is defined as at least a three hour period of visibility reduced to 1/4 mile due to falling or blowing snow with wind gusts above 35 MPH. A primary means of meeting those requirements is provided by the automated airport weather stations and one such example is shown by the featured chart for Mason City. The plot combines the period the Blizzard Warning with automated observations of visibility and wind speed. The times of reduced visibility is assumed to be due to snow in the air. The darker shaded (bluish tint) region around 6 PM on 15 March 2026 represents a period meeting blizzard criterion. There are a few other less subtle regions that represent blizzard criterion conditions not meeting the three hour requirement. As is typically the case, a blizzard warning encompasses a time period with blizzard-like conditions, but only a limited sub-region of time will verify the warning. You can run this chart for other airport locations in the state and you will find a similar story. Of course, there are caveats galore with this type of verification as airports are often in more urban areas, which tend to experience less visibility reductions than in the rural without much of obstructions.

Much of the state continues to need rain to make up for dry conditions that have persisted since about August of 2025. This is a fickle time of year though as temperatures are still yet chilly and moisture is limited, so significant rainfall events can be difficult to come by. The featured chart attempts to illustrate this by plotting the accumulated frequency of having at least an inch of precipitation accumulated after 18 March. For example, about half of previous years on record for Ames have accumulated at least an inch between 18 March and 4 April. Remarkably, a couple of years took over a month of time to accumulate just an inch or more. Unfortunately, the near term forecast is quite dry as our weather is heavily influenced by the strong western US anti-cyclone that is bringing record setting warmth to the southwestern US and beyond.

Iowans have seen quite the roller coaster of conditions so far this March with snowfalls earlier this week now giving way to very warm temperatures. On Tuesday, Des Moines reported 0.5 inches of snowfall and then a high temperature of 64°F on the next day. This seems like a rather extreme combination of daily weather variables, so a new "IEM autoplot tool" has been added in this space to list out such combination of weather events. In this case, the combination of having measurable snowfall reported and then the following day high temperature is listed out showing the highest and lowest next day high temperature values. You can find the 17-18 March 2026 event listed within this summary, but 14°F less than the maximum of 78°F back in 1918. This autoplot tool can be used to generate many different arbitrary combinations of events and then preceding or proceeding number of days weather variables. For example, the tool indicates Washington DC just had its maximum high temperature 86°F on the day before a snowfall event last week! As with the entire IEM website, your feedback is welcome and guides tool development!

The featured chart presents the daily high temperature departure from average for Sioux City for each day this year. The calculated departure on Thursday was just over 30°F above average and made for the ninth such day this year of at least 30°F. The chart nicely shows how dominant the warm weather has been since the start of February with only a few brief periods below average. Even warmer weather is expected today and on Saturday before slightly cooler weather arrives early next week, but still above average.

Saturday was incredibly warm for March with temperatures soaring into the 80s and even a few 90s over Iowa and beyond. For a couple of locations, like Cedar Rapids, a new March monthly maximum temperature record was set with a high temperature of 89°F. The featured chart presents the monthly maximum temperature records for Cedar Rapids along with a little cartoon showing the day of the given month that the record resides. Sometimes these records occur during the last few or first few days of the month, which makes the records seem arbitrary due to the non-consistent month boundaries with respect to the solar day. Anyway, those pedantic issues aside, IEM unofficial areal averaged data for Iowa will likely place Saturday as the second warmest on record for high temperature behind 29 March 1986.