How to Read the 10-Day Meteogram

[Miloslav Tlamicha]

What it is
The 10-Day Meteogram shows an extended weather forecast for the next two weeks. It combines:
• Daily weather symbols
• Ranges for maximum, average, and minimum temperatures
• Daily precipitation amounts and probability
The forecast is based on multiple weather model runs (an “ensemble”) to give a range of possible developments.
Weather Symbols
• Chosen based on the most likely daily scenario.
• In cases of low convergence (models disagree), the symbol may not perfectly match the precipitation data — this is normal.

Temperature Diagram
• Shows expected maximum and minimum temperatures for each day (local time).
• The thick middle line = most probable temperature.
• The upper and lower lines = most extreme possible values from different model runs.

Precipitation Diagram
• Bars (relative to left Y-axis) = daily precipitation amount.
• Black lines = possible range between minimum and maximum amounts.
• Probability of precipitation (0–100%) is shown below the diagram:
o Light blue: 90%
o Purple: >95%
Note: Probability and pictogram may differ for single events, but they match statistically over many cases.

How to Interpret the 10-Day Forecast
The 14-day view is most useful for spotting risks of extreme events well in advance, such as frost, heatwaves, or heavy precipitation.
Tips:
• Convergence (agreement between models) matters:
o High convergence = event more likely
o Low convergence = event still uncertain
• Consistency across weather variables makes an event more probable:
o If temperature drop, wind increase, cloud cover, and precipitation all point to the same thing — likely severe weather.
o If only one or two variables change — event may be weak or not happen at all.
• Check the forecast daily during critical periods to track changes in convergence and probability.

Commercial use
For business or operational planning, see the meteoblue B2B pages.

[market84]

Hi Miloslav,
I am a very satisfied Point+ member of Meteoblue, which to my opinion is a weather service of high quality. Nevertheless, recently got confused on how to interpret the colored day and night temperature boxes in the 10 day (or actually 14 day) forecast pictures.

I can not find the consistency of the background colors and black or white font of the temperature boxes in attached examples, especially when background color is bright lime green (BLG). In daytime temperatures, 14 degrees is BLG with white font, 16 degrees is BLG with black font, 17 and 18 degrees are pale beige/light yellow with black font and 19 and 20 degrees are BLG again, now with black font.

I have searched on the MB website and broader (AI) for an explanation on the color use, but was not able to find one. Can you explain how the model chooses the background and font colors? May there be a different reason for choosing the colors than only the corresponding temperature? Does it reflect other weather data?

Cheers, Michael.