What is the Sun doing right now?

340

updated 13 min ago

kilometres per second · Solar wind speed measured upstream of Earth

Fast enough to cover the distance from London to Sydney in 50 seconds.
Fast enough to cover the distance around Earth in 2 minutes.
Fast enough to cover the distance from Earth to the Moon in 19 minutes.

Right now the solar wind is streaming past Earth at 340 kilometres per second. The Sun's X-ray glow, which leaps when it flares, stands at B1.8 on the flare scale. Around Earth, the latest storm reading is “No storm”. The last big flare, of class M or X, began on 19 October 2026.

All of this reaches us late. The Sun's light needs 8.3 minutes to get here, and its wind about 5.1 days. Since you opened this page, the Sun has lost 0 kilograms to its light and its wind.

The Sun's X-ray brightness at Earth (GOES, 0.1–0.8 nm)

B1.8

Measured

updated 5 min ago

Planetary K-index (Kp), latest 3-hour value

4.33

Measured, with error

updated 2 h ago

Time since the last major solar flare (class M or X)

12 days

Measured, with error

Sunspot number, monthly mean (latest month)

60.3

Measured, with error

updated 30 d ago

What is the Sun?

Our star

The Sun is a star, the only one in our solar system. It is a huge ball of hot gas, mostly hydrogen and helium, held together by its own gravity. It has no solid surface. It is by far the largest thing in the solar system, and its gravity keeps every planet, asteroid and comet in orbit.

It shines because of what happens at its centre. In the core, hydrogen is squeezed and heated until it fuses into helium. That fusion releases the energy that pushes outward, keeps the Sun from collapsing and makes it shine. It has been doing this for about 4.6 billion years.

So what does it mean for a star to be "doing" something? The Sun is never still. It flares. It blows a wind of charged gas out into space. Dark spots come and go on its face, and all of this rises and falls in a rhythm of about 11 years. The numbers on this page follow each of them as they change.

1,391,400 kmThe Sun's mean diameter

About 109 times the width of Earth.
About 9.7 times the width of Jupiter.

Solar flares

Flares, from A to X

A solar flare is a sudden burst of light from the Sun. It happens above sunspots, where tangled magnetic fields snap into a calmer shape and release their energy within minutes. NASA calls flares the most powerful explosions in the solar system.

Flares shine brightest in X-rays, and NOAA's GOES satellites measure the Sun's X-rays every minute. Flares are graded by letter: A, B, C, M and X. Each letter means ten times the X-ray brightness of the one before. A number adds detail inside a class, so an M2 flare is twice as bright as an M1. Right now the Sun's X-ray glow reads B1.8.

A flare's light travels at the speed of light, so we see it the moment it arrives, 8.3 minutes after it happened. A strong one can black out shortwave radio on the daylit side of Earth. The last flare of class M or X began on 19 October 2026. Big flares are most common near the peak of the Sun's cycle.

B1.8The Sun's X-ray brightness at Earth (GOES, 0.1–0.8 nm)updated 5 min ago

The solar wind

A wind that never stops

The Sun is always losing gas from its outer atmosphere, the corona. The gas streams out in every direction as the solar wind: mostly protons and electrons, carrying the Sun's magnetic field with them. It fills a vast bubble around the Sun, so Earth lives inside the Sun's own atmosphere.

Spacecraft upstream of Earth measure the wind before it reaches us. Right now it blows at 340 kilometres per second. At that speed it would cross from the Sun to Earth in about 5.1 days. Sunlight makes the same trip in 8.3 minutes. Since you opened this page, the wind has travelled 0 kilometres.

The speed changes. Slow wind is the usual kind in the plane where the planets orbit. Faster streams pour out of coronal holes, dark patches where the Sun's magnetic field opens into space. The Sun turns once every 27 days as seen from Earth, and the wind spirals out like water from a garden sprinkler. Sometimes the Sun also hurls a giant cloud, a coronal mass ejection. The fastest reach Earth in less than a day.

340 km/sSolar wind speed measured upstream of Earthupdated 13 min ago

Solar Cycle 25

The Sun's slow rhythm

Sunspots are dark patches on the Sun's face. They are cooler than the gas around them, and they mark places where strong magnetic fields push up from inside. Monthly counts go back to 1749. The number rises and falls over about 11 years. At the low point there are few spots or none. At the high point the Sun is crowded with them, and flares and eruptions are common. With every cycle, the Sun's north and south magnetic poles swap places.

The cycle we are in, Solar Cycle 25, began in December 2019. It peaked in October 2024, when the smoothed sunspot number reached 160.9. That was well above what the experts forecast in 2019. The latest monthly sunspot number is 60.3.

So we are past the peak, on the long slope down towards the next quiet spell. NOAA expects Cycle 26 to begin some time between January 2029 and December 2032. Then the count starts to climb again.

6 y 334 d 14 hTime since Solar Cycle 25 began

What it means here

Lights in our sky

When a fast stream of wind or a coronal mass ejection reaches Earth, it can shake the magnetic field we live inside. That shaking is a geomagnetic storm. It is measured with the Kp index, and NOAA counts a storm from Kp 5. The latest reading is “No storm”.

A storm pours energy into the air high above the poles. Electrons stream down Earth's magnetic field and strike oxygen and nitrogen in the upper air, which give off light, much as a neon lamp does. That glow is the aurora. It forms two ovals around the magnetic poles. In a big storm it spreads towards the equator, and people far from the Arctic look up and see it.

Strong storms do more than paint the sky. They can strain power grids, disturb satellites and blur GPS signals. Our page on geomagnetic storms explains the scale, and the great storms of the past.

0 y 9 d 2 hTime since Earth's last geomagnetic storm (Kp 5- or higher)

Back to Earth

The sunlight we live on

Most of what the Sun does, it does with light. Earth catches only the sliver that falls on the disc our planet turns to the Sun. Even so, that sunlight carries about 9,300 times as much power as humanity uses: every fuel we burn and all the electricity we make, together.

Part of it bounces straight back to space. The rest warms the oceans and the air, drives the winds and the rain, and feeds every green leaf. Most life on Earth runs on it.

The Sun pays for this light with its own mass. Every second it turns about 5.5 billion kilograms of itself into light and wind. It is so massive that it can keep this up for a very long time. It has enough hydrogen in its core to shine for about 5 billion years more.

174 quadrillion WSunlight power that Earth intercepts

Questions people ask

Is there a solar flare right now?

Look at the X-ray level at the top of this page. It reads B1.8 right now. Flares of class M and X are the strong ones, and the last began on 19 October 2026. The reading comes from NOAA's GOES satellites, every minute.

How fast is the solar wind today?

340 kilometres per second, measured by spacecraft upstream of Earth. At that speed the wind needs about 5.1 days to travel from the Sun to us. Streams from coronal holes blow faster than the usual slow wind.

How long does sunlight take to reach Earth?

Right now 8.3 minutes. The time changes a little through the year, because Earth's distance from the Sun does. At the average distance it is 499 seconds. Earth is next closest to the Sun on 3 January 2027.

Where are we in the solar cycle?

In Solar Cycle 25, which began in December 2019 and peaked in October 2024. We are now on the way down. NOAA expects the next cycle to begin between January 2029 and December 2032.

Is the Sun losing mass?

Yes, about 5.5 billion kilograms every second, to its light and its wind. Over its whole life so far, that adds up to a very small part of its mass. It will go on shining for about 5 billion years.

Can the Sun's activity affect us on Earth?

Yes. Strong flares can black out shortwave radio on the daylit side of Earth. Geomagnetic storms can strain power grids, disturb satellites and GPS, and bring the aurora far from the poles.

How do we know?

Every number on this page, and where it comes from

Fact	Value	Certainty	Source	As of
Age of the Sun	4,567,000,000 years	Measured, with error	Science NASA Science	28 Oct 2026
Average length of the Sun's activity cycle	11 years	Measured, with error	NOAA SWPC Living Reviews in Solar Physics NASA NSSDCA	28 Oct 2026
Diameter of a regulation football (size 5)	22 cm	Measured, with error	The IFAB	27 Oct 2026
Earth's circumference at the equator	40,075 km	Measured	NASA NSSDCA	27 Oct 2026
Earth's diameter at the equator	12,756 km	Measured	NASA NSSDCA	27 Oct 2026
Great-circle distance between London and Sydney	16,990 km	Measured, with error	GeoNames GeoNames NASA NSSDCA	27 Oct 2026
Highest smoothed sunspot number of Solar Cycle 25 (13-month mean, October 2024)	160.9	Measured, with error	WDC-SILSO, Royal Observatory of Belgium SIDC, Royal Observatory of Belgium NOAA SWPC	28 Oct 2026
Humanity's average rate of energy use (total energy supply, 2024)	18.7 trillion W	Measured, with error	Energy Institute	31 Dec 2024
Jupiter's diameter at the equator	142,984 km	Measured	NASA NSSDCA	27 Oct 2026
Kp level at which a geomagnetic storm begins (G1)	5	Measured	NOAA SWPC NOAA SWPC	22 Oct 2026
Mass the Sun loses each second, to its light and its wind together	5,500,000,000 kg/s	Measured, with error	NASA NSSDCA Monthly Notices of the Royal Astronomical Society Astronomy & Astrophysics	28 Oct 2026
Planetary K-index (Kp), latest 3-hour value	4.33	Measured, with error	NOAA SWPC NOAA SWPC GFZ German Research Centre for Geosciences NOAA SWPC NOAA SWPC	30 Oct 2026, 21:00 UTC
Solar wind speed measured upstream of Earth	340 km/s	Measured	NOAA SWPC NOAA SWPC NOAA SWPC NOAA SWPC The Astrophysical Journal Journal of Geophysical Research Space Weather (AGU)	31 Oct 2026, 02:33 UTC
Speed of light in a vacuum	299,792.458 km/s	Measured	BIPM	27 Oct 2026
Sunlight power that Earth intercepts	174 quadrillion W	Measured, with error	The Astronomical Journal (IAU) NASA NSSDCA	28 Oct 2026
Sunspot number, monthly mean (latest month)	60.3	Measured, with error	NOAA SWPC SILSO, Royal Observatory of Belgium	1 Sep 2026
The International Space Station's orbital speed	7.66 km/s	Measured	CelesTrak NASA	27 Oct 2026
The Moon's average distance from Earth	384,400 km	Measured	NASA	22 Oct 2026
The Sun's distance from Earth	148,537,069 km	Measured	NASA JPL NASA NSSDCA	31 Oct 2026
The Sun's mean diameter	1,391,400 km	Measured, with error	NASA NSSDCA International Astronomical Union (via arXiv)	27 Oct 2026
The Sun's X-ray brightness at Earth (GOES, 0.1–0.8 nm)	B1.8	Measured	NOAA SWPC NOAA SWPC	31 Oct 2026, 02:41 UTC
Time since Earth's last geomagnetic storm (Kp 5- or higher)	0 y 9 d 2 h	Measured, with error	GFZ Helmholtz Centre for Geosciences, Potsdam GFZ Helmholtz Centre for Geosciences, Potsdam	28 Oct 2026
Time since Solar Cycle 25 began	6 y 334 d 14 h	Measured	NASA NOAA SWPC	28 Oct 2026
Time since Solar Cycle 25 peaked	2 y 29 d 14 h	Measured, with error	SIDC, Royal Observatory of Belgium NOAA SWPC NASA Science	28 Oct 2026
Time since the last major solar flare (class M or X)	12 days	Measured, with error	NOAA NCEI NOAA SWPC NOAA SWPC	28 Oct 2026
Time sunlight takes to reach Earth, at the mean Earth–Sun distance (1 au)	8 m 19 s	Measured	International Astronomical Union (hosted by SYRTE, Observatoire de Paris) BIPM NASA NSSDCA	28 Oct 2026
Time the Sun takes to turn once as seen from Earth (synodic, Carrington rotation)	27 days	Measured	Wilcox Solar Observatory, Stanford University	28 Oct 2026
Time the Sun will go on burning hydrogen in its core, from now	5,000,000,000 years	Estimated	NASA Science The Astrophysical Journal	28 Oct 2026
Time until Earth's next perihelion (closest to the Sun)	63 d 23 h 46 m 52 s	Measured	NASA JPL US Naval Observatory	28 Oct 2026

Every sunrise shows a star at work: flaring, blowing its wind, turning slowly through its cycle. What will you think of the next time you feel it on your face?