Sun · irradiance
The energy we receive
Total solar irradiance is the energy received at the top of the atmosphere, about 1,361 W/m². It varies by only about 0.1 % over the cycle; sunspots lower it, faculae raise it.
Irradiance (NRLTSI2)
1,362.08 W/m²
Range since 1978
6.59 W/m²
Relative variation
0.48 %
NRLTSI2 daily total solar irradiance (NOAA CDR via LASP LISIRD) · NOAA Climate Data Record, public domain; cite Coddington et al. (2016) · 10/23/26
Illustrative surface and corona; spots from the latest monthly sunspot number.
Latest available day
1,362.08 ± 0.37 W/m²
2023-12-31
NRLTSI2 daily total solar irradiance (NOAA CDR via LASP LISIRD) · NOAA Climate Data Record, public domain; cite Coddington et al. (2016) · 10/23/26
Daily maximum (satellite era)
1,363.23 ± 0.99 W/m²
1979-12-12
NRLTSI2 daily total solar irradiance (NOAA CDR via LASP LISIRD) · NOAA Climate Data Record, public domain; cite Coddington et al. (2016) · 10/23/26
Daily minimum (satellite era)
1,356.64 ± 1.63 W/m²
2003-10-30
NRLTSI2 daily total solar irradiance (NOAA CDR via LASP LISIRD) · NOAA Climate Data Record, public domain; cite Coddington et al. (2016) · 10/23/26
Days available
51,864
1/1/82 → 12/31/23
before Nov 17, 1978: proxy reconstruction (estimated values)
NRLTSI2 daily total solar irradiance (NOAA CDR via LASP LISIRD) · NOAA Climate Data Record, public domain; cite Coddington et al. (2016) · 10/23/26
Total solar irradiance since 1882, yearly mean
NRLTSI2 daily total solar irradiance (NOAA CDR via LASP LISIRD) · NOAA Climate Data Record, public domain; cite Coddington et al. (2016) · 10/23/26
Show the data as a table
Daily irradiance, last three available years
NRLTSI2 daily total solar irradiance (NOAA CDR via LASP LISIRD) · NOAA Climate Data Record, public domain; cite Coddington et al. (2016) · 10/23/26
Show the data as a table
Method and sources
NRLTSI2 is the model of the NOAA “solar irradiance” Climate Data Record: irradiance is reconstructed from sunspot darkening and facular brightening, calibrated against the satellite measurements (SORCE/TIM) available since 1978 (Coddington et al., 2016). Unit: W/m² at 1 astronomical unit.
Values before 17 November 1978 (start of continuous measurements) are flagged “estimated”; the model uncertainty is imported with each value.
Reading these data
This is a model constrained by observations, not a series of raw measurements. The version served by LISIRD may stop several months before today; the date of the last point is shown.
SOURCES OF THIS PAGE
- NRLTSI2 daily total solar irradiance (NOAA CDR via LASP LISIRD)
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Coddington, O., Lean, J. L., Pilewskie, P., Snow, M., & Lindholm, D. (2016). A Solar Irradiance Climate Data Record. Bulletin of the American Meteorological Society, 97, 1265–1282. Data: NRLTSI2 via LASP LISIRD.
· doi:10.1175/BAMS-D-14-00265.1 · source page ↗
Licence : NOAA Climate Data Record, public domain; cite Coddington et al. (2016) · retrieved on Oct 23, 2026 · SHA-256 f6ca2f1a23d4…