Costa Rica Climate – July 2026 Update
Top 5 Cities: San José, Alajuela, Cartago, Heredia, and Liberia
Summary
Conditions across Costa Rica reached near-record heat in July 2026, marking the 2nd warmest instance of the month on record as temperature anomalies climbed across Central America. A stark climate split defined the month, with severe rainfall deficits triggering drought warnings along the Pacific coast and Central Valley while tropical waves battered the Caribbean slope with heavy downpours. The intensifying warmth is closely tied to a moderate El Niño forecast to peak at Very Strong in Sep-Nov, with elevated temperatures expected to persist over the coming months.
This month in numbers
Costa Rica recorded an average temperature of 24.32°C in July 2026, sitting 1.5°C above the 1961–1990 baseline and ranking as the 2nd warmest instance on record, behind only the 24.34°C peak set in 2023. The broader three-month period was similarly exceptional, with the May–July 2026 average of 24.48°C (+1.4°C anomaly) ranking as the 2nd warmest such window on record, trailing only the 2023 record of 24.59°C. This regional heat mirrored broader global patterns, as the global land temperature for July 2026 reached 15.8°C (+1.6°C anomaly), placing 3rd overall globally.
What changed
Temperatures across Costa Rica steadily built through the first half of the year, transitioning from a near-average February (+0.0°C) to moderate warmth in March and April (+0.5°C), before surging to +1.2°C in May, +1.4°C in June, and +1.5°C in July. Across North America, where the regional group average anomaly stood at +1.72°C, Costa Rica tracked 0.19°C below the group mean. In long-term context, the country's average temperature reached 23.42°C in 2025 (its 9th warmest year), reflecting a warming trend of +0.70°C since 1961–1990, while the all-time warmest year remains 2024 at 23.86°C.
What’s driving change?
The primary engine behind Central America's shifting climate is ENSO, with the tropical Pacific currently in a moderate El Niño phase with a RONI anomaly of +0.98°C, as detailed on ENSO. In Costa Rica, El Niño historically brings a 65% chance of warmer, drier conditions across the Central Valley and Pacific slope while disrupting tropical rainfall. This influence was amplified by dynamics, elevating land temperatures relative to surrounding sea surfaces. While no local events met the threshold for our live extreme weather tracker, the thermal background sharpened local contrasts between Pacific drought and Caribbean downpours.
Looking ahead
Seasonal models project a 93% probability of a Very Strong El Niño developing over the coming months, with official forecasts pointing to an October–December peak of +2.7°C RONI that will likely sustain above-average temperatures and drought pressure across Central America through late autumn.
Generated by Gemini from climate data and web sources
At a Glance
Temperature – Average
Climate Map – Global
Source: NOAA Climate at a Glance (countries & continents) · Met Office (UK) · US states & climate regions. Anomalies are vs the 1961–1990 baseline. See methodology.
Typical Climate – Costa Rica
Köppen Af · TropicalCosta Rica has a tropical climate (Köppen Af: Tropical rainforest), with only modest temperature variation through the year, but a pronounced wet and dry season. May is typically the warmest month, averaging 24.2°C, while January is the coldest at 22.6°C. Annual precipitation averages around 2987mm, concentrated mostly in the wet season.
Monthly climate normals (2016–2025) - bar colour and height show average temperature, the shaded area shows average monthly precipitation.
Data: Our World in Data / NOAA (precipitation: GPCC (DWD); frost: World Bank CCKP).
Long-Term Trends
Combined Timeline – Costa Rica
Right axis: everything else standardized to standard deviations (σ) from its own average, since mm/hours/days aren't directly comparable to °C or to each other.
Data: Our World in Data / NOAA (precipitation: GPCC (DWD); frost: World Bank CCKP).
Heatwave Days – Costa Rica
Warm Spell Duration Index (WSDI) - the WMO/ETCCDI heatwave measure: days in a 6+ day run above the local 90th-percentile temperature for that time of year.
Data: World Bank Climate Change Knowledge Portal (ERA5-derived). Refreshed roughly 1-2x/year, ~7-8 months behind present.
Year-on-Year Trends
The 4byo Climate Helix – Costa Rica
Data: Our World in Data / NOAA (precipitation: GPCC (DWD); frost: World Bank CCKP).
Monthly Temperature – Costa Rica
Background lines show the last 40 years (plus the record year and its opposite, wherever they fall).
Data: Our World in Data / NOAA (precipitation: GPCC (DWD); frost: World Bank CCKP).
Records – Costa Rica
Our World in Data / NOAA (precipitation: GPCC (DWD); frost: World Bank CCKP) - Anomalies vs 1901-2000 mean
Shifting Seasons
Wet / dry seasonsKöppen Af · TropicalCosta Rica doesn't have a warm/cold cycle - its monthly temperature range is only 1.7°C across the year - but it does have a strong wet/dry cycle (the wettest month gets 5× as much rain as the driest). So we track how the wet season has shifted instead.
Monthly precipitation climatology. A “wet month” exceeds the baseline monthly mean (dashed gold line). Biggest month-to-month shift: Aug (-66 mm, -18%).
Data: Our World in Data / NOAA (precipitation: GPCC (DWD); frost: World Bank CCKP).
Climate Systems
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Emissions & Energy
Explore
Explore Climate Data
Data Sources
Data Sources for Costa Rica
Every figure on this page is sourced from official, openly published climate datasets. Anomalies are calculated against the 1961–1990 baseline (temperature) and 1991–2020 (rainfall, sunshine, frost) - see the Methodology & Sources page for the complete dataset list and update calendar.
Country-level temperature anomaly, sourced from Copernicus ERA5 and Hadley HadCRUT5.
Annual country and global CO₂ emissions, from the Global Carbon Project.
Monthly rainfall - Global Precipitation Climatology Centre (DWD) preferred, World Bank CCKP/CRU TS fallback where GPCC lacks direct coverage.
Frost Days and Heatwave Days (Warm Spell Duration Index), ERA5-derived. World Bank Climate Change Knowledge Portal.
Monthly snow water-equivalent, Global Precipitation Climatology Centre (DWD).
FAQs
FAQs
How is the climate in Costa Rica changing?
Costa Rica is warming in line with the rest of the world. The page above shows the latest monthly temperature anomaly versus the 1961-1990 baseline, the long-term annual trend, and the region's rank in the historical record. The headline panel also shows the long-term trend rate per decade and the warmest and coolest years on file.
What is the climate like in Costa Rica?
Costa Rica has a tropical climate (Köppen Af: Tropical rainforest), with only modest temperature variation through the year, but a pronounced wet and dry season. May is typically the warmest month, averaging 24.2°C, while January is the coldest at 22.6°C. Annual precipitation averages around 2987mm, concentrated mostly in the wet season.
Where does the climate data for Costa Rica come from?
Climate data for Costa Rica comes from Our World in Data, sourcing Copernicus ERA5 and HadCRUT5 (national temperature anomaly) and the Global Carbon Project via Our World in Data (CO₂ emissions), refreshed every month, when the upstream temperature and rainfall data are refreshed.
What is the climate baseline used on this page?
Anomalies on this page are calculated against the 1961-1990 climatological baseline, which is the standard reference period used by the Met Office, NOAA, IPCC and most national climate services. Some panels also show the source-native 1901-2000 (NOAA) or 1991-2020 (WMO) baselines for verification. See Methodology & Sources for the full reference.
Which areas does the Costa Rica climate data cover?
The Costa Rica climate profile covers San José, Alajuela, Cartago, Heredia and surrounding areas. Temperature, rainfall and emissions data for Costa Rica
How often is the Costa Rica climate update refreshed?
The Costa Rica climate update is refreshed monthly, typically a few days after the previous month closes and the upstream provider (Met Office HadUK-Grid, NOAA Climate at a Glance, Copernicus ERA5 or the Global Carbon Project) publishes its update. See the Climate Rankings for cross-region comparisons.
What counts as a Heatwave Day on the Costa Rica climate page?
Heatwave Days use the Warm Spell Duration Index (WSDI) - the WMO/ETCCDI-standard heatwave measure: days that are part of a run of 6 or more consecutive days above the local 90th-percentile temperature for that calendar day. The 90th-percentile threshold varies by time of year (a hot day in January is judged differently to one in July) but is fixed to the 1961-1990 baseline for every year shown - it does not shift as the climate warms, which is why Heatwave Days trend upward over time.
Does the Costa Rica climate page include frost and snow data?
Yes. Frost Days (days with a minimum temperature below 0°C, World Bank CCKP) and snow water-equivalent (GPCC) are shown alongside temperature and precipitation, each measured against the 1961-1990 baseline where a like-for-like historical comparison is available.