Global Average Temperature 2025

[chubbs]

CERES has been updated through July. Recent months have been increasing erratically a sign that the enso-cycle bottom has been passed. The three-year average net radiation remains at a high level, well above the initial heat imbalance when CERES started collecting data in 2000. The recent net radiation uptick is also consistent with the large rise in ocean-heat content in 2nd quarter which was posted above. Both energy balance metrics indicate that the earth continues to warm rapidly.

[donsutherland1]

Through October 10th, 2025 has the 3rd warmest start to October globally on the ERA-5 dataset. The five warmest October 1-10 periods are:

1. 15.72°C, 2023
2. 15.59°C, 2024
3. 15.45°C, 2025
4. 15.38°, 2015
5. 15.30°C, 2020

With the warm global forecast (generally 0.8°C-1.0°C)  on the ECMWF weeklies, there is a growing chance that 2025 could join 2023 and 2024 as the only years with an October mean temperature of 15.00°C or above.

[donsutherland1]

October 2025 has a global mean temperature of 15.29°C through October 20th (ERA-5). That ranks as the third warmest October 1-20 period on record. October 2025 remains on track to finish as the third warmest October on record (likely with a monthly mean temperature of 15.00°C or above). To miss, the October 21-31 period would need to see sustained cool readings that last occurred in 2013. That is improbable with today's greater greenhouse gas forcing.

[chubbs]

18 hours ago, donsutherland1 said:

October 2025 has a global mean temperature of 15.29°C through October 20th (ERA-5). That ranks as the third warmest October 1-20 period on record. October 2025 remains on track to finish as the third warmest October on record (likely with a monthly mean temperature of 15.00°C or above). To miss, the October 21-31 period would need to see sustained cool readings that last occurred in 2013. That is improbable with today's greater greenhouse gas forcing.

Per gfs, the end of October is going to be warm. The highest global anomalies so far this year. 

[chubbs]

Satellite SST estimates show that the 23/24 nino cycle had a similar warming effect on global SST as the 2015/16 nino. Together these two nino's have triggered roughly 0.4C of global SST warming.

[GaWx]

3 hours ago, chubbs said:

Satellite SST estimates show that the 23/24 nino cycle had a similar warming effect on global SST as the 2015/16 nino. Together these two nino's have triggered roughly 0.4C of global SST warming.

Didn’t the 2023 warming come in way too early to be attributed to the 2023-4 El Niño? I distinctly recall the discussions here and elsewhere about that because it started in spring (as early as March) and also the possibility that Hunga Tonga was the main factor due to the enormous amount of water vapor sent up into the stratosphere. All of this remains mysterious to me.

[Typhoon Tip]

Kinda interesting.  Not sure if there's any actual predictive usefulness to this philosophy outlined below, but could we be setting up 2026 as another ...holy shit, didn't see that comin'  global leap in temperature?

This is the current winter escape curve in the southern hemisphere ( provided by https://climatereanalyzer.org/clim/t2_daily/?dm_id=sh  ).  It's presently the warmest October on record down there?  That's equivalent to late February up here.   So then heading through their "March" and "April" ...when solar really is accelerating ... where is this curve destined?  (dark rust)

Intuitively/simple additive thinking might be setting up a high launch pad for the world, whence the N. Hem. spring of 2026 starts dumping in its typically warm quota ( due to having greater land integral).. The ongoing tendency that our immediately ensuing winter will end up above normal overall (not compensating in the averaging)  notwithstanding.    Just some wondering here -

[chubbs]

3 hours ago, GaWx said:

Didn’t the 2023 warming come in way too early to be attributed to the 2023-4 El Niño? I distinctly recall the discussions here and elsewhere about that because it started in spring (as early as March) and also the possibility that Hunga Tonga was the main factor due to the enormous amount of water vapor sent up into the stratosphere. All of this remains mysterious to me.

Per link below the 2023 warming has been attributed to El Nino. The article does say that the warming came on more suddenly and lasted longer than a typical nino. But that is probably due the increasingly positive radiation balance due to cloud feedback and air pollution control. I haven't seen the Hunga Tonga volcano linked to significant warming in a scientific paper. 

https://www.science.org/doi/10.1126/science.adt7207

 

[GaWx]

2 hours ago, chubbs said:

Per link below the 2023 warming has been attributed to El Nino. The article does say that the warming came on more suddenly and lasted longer than a typical nino. But that is probably due the increasingly positive radiation balance due to cloud feedback and air pollution control. I haven't seen the Hunga Tonga volcano linked to significant warming in a scientific paper. 

https://www.science.org/doi/10.1126/science.adt7207

 

 Thanks Charlie,

 This tells me that they still don’t know why there was a sudden spike in the first half of 2023. Just a lot of speculation.

 

[bluewave]

It could just be that mid-latitude Pacific warming is acting as a higher latitude El Niño. So this is why the warming occurred earlier in 2023 than during past El Niño events. Plus the warming lingered longer than previous El Niños. 

 

[roardog]

32 minutes ago, GaWx said:

 Thanks Charlie,

 This tells me that they still don’t know why there was a sudden spike in the first half of 2023. Just a lot of speculation.

 

It just seems crazy to me that a volcano can throw as much water vapor into the atmosphere as this one did and it’s pretty much shrugged off as nothing to see here.

[GaWx]

21 minutes ago, bluewave said:

It could just be that mid-latitude Pacific warming is acting as a higher latitude El Niño. So this is why the warming occurred earlier in 2023 than during past El Niño events. Plus the warming lingered longer than previous El Niños. 

 

Hey Chris,

If the sudden early 2023 spike was due to sharp mid-latitude Pacific warming, then what caused that sharp early 2023 Pacific warming?

[bluewave]

19 minutes ago, GaWx said:

Hey Chris,

If the sudden early 2023 spike was due to sharp mid-latitude Pacific warming, then what caused that sharp early 2023 Pacific warming?

The best guess so far is the big reduction in sulphur dioxide emissions over the last decade from China and shipping lead to less clouds over the Pacific which was masking the CO2 emissions warming. 
 

https://e360.yale.edu/digest/asia-air-pollution-sulfates-warming

 

[GaWx]

37 minutes ago, bluewave said:

The best guess so far is the big reduction in sulphur dioxide emissions over the last decade from China and shipping lead to less clouds over the Pacific which was masking the CO2 emissions warming. 
 

https://e360.yale.edu/digest/asia-air-pollution-sulfates-warming

 

Chris,

 Thanks. I still don’t see why the reduction of sulfates would cause such a sudden warming in the Pacific over a short period in early 2023. That still seems odd and thus it’s pretty fascinating!