Sun news for March 24-25, 2025. High-speed solar wind from a large coronal hole is expected to reach Earth and cause G1-G2 (minor-moderate) geomagnetic storms later today (March 25) into tomorrow. Clear skies! Image via UK MetOffice.
Sun news March 25: Beautiful auroras tonight?
(11 UTC to 11 UTC)
Today’s top story: Space weather experts are predicting beautiful auroral displays at northerly latitudes tonight! That’s because a giant coronal hole is now facing Earth and sending a stream of fast solar wind our way. This stream is expected to catch up with slower wind ahead of it, forming a co-rotating interaction region (CIR): a powerful structure that can stir up Earth’s magnetic field. This blast of solar wind could trigger geomagnetic activity tonight and into tomorrow. In fact, NOAA has issued a G2 (Moderate) geomagnetic storm alert for March 25. Clear skies and good luck, aurora hunters! And in other news, Mercury passed between Earth and the sun yesterday, with the SOHO spacecraft watching on. Take a look at the imagery below.
Sun-Earth highlights in the past day
Flare activity remains at low levels with only C flares fired over the past 24 hours. However, flare production has increased, with 21 total C flares in the past day. The largest event was a C3.4 flare at 0:40 UTC on March 25 from active region AR4036 in the northwest. AR4036 produced 13 of the day’s flares.
There are four active regions on the sun. AR4036 retained its beta-gamma magnetic configuration, and it is now the most productive region we can see. The remaining active regions show simpler alpha or beta configurations, remaining stable or in decay.
Blasts from the sun? An Earth-directed coronal mass ejection (CME) hurled from the sun on March 22 arrived over the past day, but did not have much impact. No other Earth-directed CMEs were observed in available coronagraph imagery.
Solar wind: Solar wind speeds dropped, ranging from ~360 km/s to ~376 km/s. These solar wind conditions reflect a waning coronal hole influence. The total interplanetary magnetic field (IMF) remained low. The Bz component (north-south orientation) fluctuated between north and southward. It is currently southward oriented.
Geomagnetic activity: Our geomagnetic field’s activity peaked at Kp = 4 during a 3-hour period late on March 24. For the rest of the day the Kp index was between 2 and 3.
What’s ahead? Sun-Earth forecast
Low-to-moderate flare activity is expected over the next 24 hours, with a chance of isolated M-class flares. The chance for M flares is 30% today, and the chance for X flares is 5% today.
Geomagnetic activity forecast: G1 (minor) to G2 (moderate) storms levels are anticipated for later today, March 25, due to a co-rotating interaction region (CIR) and fast solar wind from a coronal hole. Conditions for G1 storming may be extend through March 26. Clear skies aurora watchers!
See the white dot moving faster than the background stars in this imagery from the sun-observing SOHO spacecraft? That’s Mercury, heading toward inferior conjunction – its pass between us and the sun – yesterday. Notice that it gets dimmer as it moves between us and our star. Just like the moon as it moves toward new moon, Mercury dims as we see less and less of its sunlit side, almost disappearing entirely at the point of inferior conjunction. Image via SOHO.March 25, 2025. We’ve been observing jets and fiery filament eruptions in the southeast, while a gorgeous long-lasting prominence adorned the northwest limb (edge). GOES-16 SUVI 304 angstrom. Image via NOAA.This image shows sun activity – with the most active regions labeled – as of 3 UTC on March 25, 2025. Original image, without labels, via NASA SDO. Courtesy of NASA/SDO and the AIA, EVE, and HMI science teams, with labeling by EarthSky. Today’s sun is posted by Armando Caussade. Why are east and west on the sun reversed?
Sun news March 24: Enormous coronal hole to stir things up
(11 UTC to 11 UTC)
Geomagnetic activity is expected to heat up over the next few days. That’s because a giant coronal hole will soon be facing Earth and sending its fast solar wind our way. Plus, this stream will catch up with slower wind ahead of it, forming a powerful structure known as a co-rotating interaction region (CIR). This blast of solar wind could really stir up geomagnetic activity on Earth tomorrow and Wednesday.
Sun-Earth highlights in the past day
Flare activity has dropped to low with only 13 C flares over the past day. The largest event was a C5.2 flare at 7:37 UTC on March 24 from active region AR4035 just north of the solar disk’s center.
There are eight active regions on the Earth-facing solar disk. AR4036 continues to grow in size and is the only active region showing a beta-gamma magnetic configuration, indicating a potential for stronger flares. The remaining active regions show simpler alpha or beta configurations and remain stable or in decay.
Blasts from the sun? No Earth-directed coronal mass ejections (CMEs) were detected in the past 24 hours. A faint halo coronal mass ejection from a filament eruption observed on March 21 arrived overnight. A second CME from March 22 may arrive today.
Solar wind: Solar wind speeds decreased from ~480 km/s to ~400 km/s. The solar wind conditions reflect waning coronal hole influences. The total interplanetary magnetic field (IMF) remained low. The Bz component (north-south orientation) fluctuated between north and southward.
Geomagnetic activity: Our geomagnetic field’s activity ranged from Kp = 1 to 4. Kp = 4 was reached after the faint CME reached Earth early on March 24. The geomagnetic field reached G1–G2 (minor–moderate) geomagnetic storm levels over the past day, due to the CME and coronal hole high-speed stream (solar wind) effects.
Sun news for March 24, 2025. A giant coronal hole is rotating into a geoeffective position, meaning its high-speed solar wind will soon be stirring up our local space environment. Also, as the fast solar wind plows into slower solar wind ahead of it, a co-rotating interaction region (CIR) could form, increasing its heft when it hits Earth. Image via SDO/ NASA.
View at EarthSky Community Photos. | Tameem Altameemi in Dubai, United Arab Emirates (UAE), captured this filtered image of the sun on March 22, 2025. Tameem wrote: “I captured this high-resolution image of the sun from Dubai using a dedicated hydrogen-alpha solar telescope. The image reveals intricate surface details, including solar filaments, active regions, and dramatic prominences rising from the solar limb. For scale, a small Earth icon is included to highlight the immense size of our star. Hydrogen-alpha imaging allows us to witness the dynamic and ever-changing nature of the sun’s chromosphere, offering a glimpse into solar activity that affects space weather and our technological systems on Earth.” Thank you, Tameem!
The sun in recent days
This image shows sun activity – with the most active regions labeled – as of 6 UTC on March 24, 2025. Image via NASA/ SDO.This image shows sun activity – with the most active regions labeled – as of 6 UTC on March 23, 2025. Image via NASA/ SDO.
Sun images from our community
View at EarthSky Community Photos. | Patricio León in Santiago, Chile, captured this filtered image of the sun on March 24, 2025. Patricio wrote: “Sunspots AR4036 and AR4030 are ready to depart, leaving an almost blank solar face.” Thank you, Patricio!View at EarthSky Community Photos. | Mario Rana in Hampton, Virginia, captured this filtered image on March 23, 2025. Mario wrote: “Hydrogen-alpha image of the sun with nice active regions, filaments, and prominences.” Thank you, Mario!View at EarthSky Community Photos. | Tameem Altameemi in Dubai, United Arab Emirates (UAE), captured this filtered image of the sun on March 22, 2025. Tameem wrote: “I captured this high-resolution image of the sun from Dubai using a dedicated hydrogen-alpha solar telescope. The image reveals intricate surface details, including solar filaments, active regions, and dramatic prominences rising from the solar limb. For scale, a small Earth icon is included to highlight the immense size of our star. Hydrogen-alpha imaging allows us to witness the dynamic and ever-changing nature of the sun’s chromosphere, offering a glimpse into solar activity that affects space weather and our technological systems on Earth.” Thank you, Tameem!View at EarthSky Community Photos. | Jim Militello in Tucson, Arizona, captured this filtered image of the sun on March 21, 2025. Jim wrote: “Hydrogen-alpha image showing active regions, filaments, and some nice prominences.” Thank you, Jim!
Are you a fan of sun images? We invite you all to send us your beautiful recent photos of sunspots and auroras. We love receiving them and sharing them! And to those of you who’ve already posted a photo to our community page, thank you.
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Bottom Line: Sun news March 25, 2025. High-speed solar wind from a giant coronal hole should soon stir up the local space environment. Prepare for auroras tonight! Find archived versions of past days’ sun news here.
C. Alex Young
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About the Author:
C. Alex Young is a solar astrophysicist studying the Sun and space weather. Alex is passionate about sharing science with diverse audiences. This led him to start The Sun Today with his designer wife, Linda. First through Facebook and Twitter then adding an extensive website thesuntoday.org, the two work together to engage the public about the Sun and its role in our solar system. Alex led national engagement efforts for the 2017 total solar eclipse. He is the Associate Director for Science in the Heliophysics Science Division at NASA Goddard Space Flight Center.
Raúl Cortés
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About the Author:
Raúl Cortés studied engineering at the Autonomous University of Nuevo León in Monterrey, Mexico, obtained a scholarship to continue his studies in Japan and after returning to Monterrey he got credits on MBA from the Graduate School of Mechanical and Electrical Engineering Faculty. He became a teacher at the University UANL teaching Math and Physics and dedicated the rest of his professional career to serve in engineering areas for USA, Japan and Germany based corporations. His passion for the skies go back to when he was a child, always intrigued about the stars and constellations and reading and researching about the matter. From 2010 on, he dedicated his attention to photographing the stars, constellations, the moon and the sun. Raúl’s work on his photography has been published and posted on the ESC as well as in other platforms and has gained attention to be published by local Monterrey newspapers.
Armando Caussade
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About the Author:
Armando is known primarily as an astronomy educator, after 30+ years of extensive public outreach and 10 years teaching in colleges. As one of only a handful of science communicators in Puerto Rico during Comet Halley’s last visit, he assumed a pioneering role starting in 1985 when science was just beginning to enter the collective mindset. Over the years, his work as a teacher, speaker and writer, inspired people to pursue interests in science and brought enduring change to Puerto Rican culture. After being accepted into the 2014–2015 Antarctic season of PolarTREC, Armando was assigned to the Amundsen-Scott South Pole Station, where in 2015 he successfully conducted 10 days of work at the IceCube Neutrino Observatory. His affiliations include Ana G. Méndez University, Cupey campus (2014 to 2021), the University of Puerto Rico, Aguadilla campus (2015 to 2017), NASA JPL’s Solar System Ambassadors (2004 to 2006), and NASA Space Grant (2017 to 2019) where he served as an affiliate representative.
