Summary
The last three years have reached record global temperatures. Warming is accelerating so fast that even through the noise of daily temperature data, it’s clear how abnormal the past few years have been. We are in uncharted territory.
This visualization keeps close tabs on daily global air surface temperatures. It is automatically updated daily.
The data
This visualization shows daily global temperature compared to historical temperatures before humans started emitting greenhouse gases in large quantities. Here’s how it works:
This chart shows, for each day, how much Earth's average temperature differs from pre-industrial times (1850-1900). We use this historical baseline to clearly show warming relative to global climate targets like the 1.5°C threshold established in the Paris Agreement.
The data covers the entire Earth (from 90° South to 90° North latitude, and all longitudes) and is updated daily, with a 5-6 day delay due to data processing times. Specifically, the metric displayed is the surface air temperature, which is the temperature 2 metres above the ground or ocean surface.
The temperatures come from ERA5, which is the fifth generation ECMWF (European Centre for Medium-Range Weather Forecasts) reanalysis dataset. ERA5 combines actual observations with physics-based models to create a complete picture of global climate.
Each day's global temperature is calculated by:
- Taking measurements eight times throughout the day (at midnight, 3am, 6am, 9am, noon, 3pm, 6pm, and 9pm UTC)
- Applying a weighted average that accounts for the fact that gridcells are not all equal in size (grid squares near the poles cover less actual area than squares near the equator)
- Averaging these readings to get a daily value
- Comparing this to the pre-industrial baseline using adjustment values from Copernicus Climate Change Service (C3S)
Citation
Copernicus Climate Change Service (C3S) (2023): ERA5 hourly data on single levels from 1940 to present. Copernicus Climate Change Service (C3S) Climate Data Store (CDS). 10.24381/cds.adbb2d47.
