Mid-March is the time when ice coverage in the Arctic Basin reaches its maximum. We’ve already seen how there was less ice on the water in mid-March on the maximum day than on any other March during the satellite period (1979-Present). Still, there is a very great day-to-day variation in Sea Ice Extent due to local weather and current conditions, so perhaps a better indicator of overall SIE decline is given by the AVERAGE Extent for the entire month. Well, the mean SIE for the entire month has now been calculated, and the results published in the time-series graph below, where the mean SIE for 3/2025 is compared to all the other March Means since 1979.
So even on the month where Sea Ice Extent is highest, the current March Mean SIE is the lowest it has ever been since the satellite measurements began. In 46 years, according to the blue linear regression line, the Mean March Max has dropped from 16.1 to 14.4 million square kilometers.
Keep an eye on nsidc.org. Its only a matter of time before government funding for this resource is cut and this indicator (and all the other metrics and analyses from the National Snow and Ice Data Center) is removed from the national debate. Our government is not mistaken about global warming. It knows perfectly well what is going on with the climate. They are just trying to ignore it, or at least, make sure we don’t find out about it.
Figure 1b. The graph above shows Arctic sea ice extent as of April 2, 2025, along with daily ice extent data for four previous years and the record low year. 2024 to 2025 is shown in blue, 2023 to 2024 in green, 2022 to 2023 in orange, 2021 to 2022 in brown, 2020 to 2021 in magenta, and 2011 to 2012 in dashed brown. The 1981 to 2010 median is in dark gray. The gray areas around the median line show the interquartile and interdecile ranges of the data. Sea Ice Index data. — Credit: National Snow and Ice Data Center