IESO 2026 exam dates
Each row links to the organiser's original notice.
- Aug23International RoundInternational
Sunday, 23 Aug 2026 - 24 Aug 2026
Source: IESO 2026 TurinUpdated 07 Oct 2026
Past
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About IESO
The International Earth Science Olympiad (IESO) is the annual international Earth science competition of the International Geoscience Education Organisation (IGEO), for secondary school students who are not older than 18 on 1 July of the competition year. Each participating country sends a team of four students, chosen through its own national selection, to compete in geology, geophysics, meteorology, oceanography, terrestrial astronomy and environmental science.
Please note that a different contest, the International Environmental Science Olympiad run by International Academic Competitions in the United States, uses the same abbreviation. This page is about the Earth Science olympiad of IGEO: its levels, rounds, IESO exam format and how to use IESO past papers to prepare.
Overview
IESO was first held in October 2007 in Daegu, South Korea, with eight countries taking part. It is organised by IGEO, a body that works to improve geoscience education worldwide and is affiliated with the International Union of Geological Sciences (IUGS). A different country hosts the olympiad each year. The 2020 edition was cancelled because of the COVID-19 pandemic and the following editions were held online, before in-person competitions resumed in Beijing (2024) and Jining (2025), both in China. The 19th IESO took place in Turin, Italy, in 2026, with teams from around 40 countries.
IESO is built around the Earth system approach: the Earth is studied as connected spheres of rock, water, air and life, together with its place in space. Besides individual exams, the olympiad includes cooperative activities in which students from different countries work together, which is unusual among international science olympiads.
IESO levels and grades
IESO has a single level for secondary school students. Eligibility is based on age and school status.
| Level | Grade | Notes |
|---|---|---|
| Secondary | Grade 9-12 | Not older than 18 on 1 July of the competition year, and still at secondary school (not enrolled at a university or college). |
National selection bodies may add their own rules, so check the conditions in your country.
Rounds
- National selection. Each country chooses its team of four in its own way. In India, for example, the Geological Society of India runs an entrance test, then a training camp with the Indian National Earth Science Olympiad, and the top four are selected for IESO. In the United States the team is selected by the United States Earth Science Organization. Not every country takes part, and students cannot enter IESO as individuals.
- International olympiad. The national teams, each with two mentors, meet in the host country for about a week of exams, fieldwork and cultural programmes.
IESO exam format and scoring
The international olympiad has four main components:
| Component | Format | Taken by | Awards |
|---|---|---|---|
| Written Test | Multiple-choice questions that ask students to analyse data and often link more than one Earth system | Individual | Individual medals |
| Practical Field Test | Field observations and/or small laboratory experiments | Individual | Individual medals |
| International Team Field Investigation (ITFI) | Mixed international teams answer a research question through fieldwork, lab work and data analysis, then present their findings | Team of students from different countries | Team awards |
| Earth Systems Project (ESP) | Mixed international teams research an Earth systems topic, often linked to the host region, and present a poster | Team of students from different countries | Team awards |
Individual medals are based on the written and practical tests. Roughly 10% of participants receive gold, 20% silver and 30% bronze. IGEO does not publish a fixed number of questions or points that applies every year, as each host's examination board prepares the papers.
When is it held
The international olympiad usually takes place in August or September. National selection runs earlier in the year; in India, for example, the national training camp is usually held around May or June. Dates differ by country and by year, so follow the national organiser in your country.
How to prepare with past papers
- Start with official past papers. IGEO publishes a collection of past IESO exams on its website, and some national organisations also share their selection papers. These are the best guide to the style of questions.
- Practise reading data. Written Test questions are built around maps, graphs, tables, diagrams and photos. Work on reading geological maps, weather charts, climate graphs and sky charts quickly and accurately.
- Think in systems. Many questions connect two spheres, for example how volcanic activity affects the atmosphere or how ocean currents shape climate. When you review a past question, ask which Earth systems it links.
- Cover all six areas. Students often know one field well, such as astronomy or geology, and lose marks in the others. Use past papers to find your weakest area.
- Get outside. The practical test and team investigations need field skills such as identifying rocks and minerals and recording observations. These cannot be learned from a screen.
On Edupiad you can practise IESO written test questions from past papers online with a timer, automatic marking and a question-by-question review afterwards. Coverage depends on which years have been added, and not every question has a worked solution. The practical, field and team components cannot be practised online.
Frequently asked questions
Is IESO the International Earth Science Olympiad or the Environmental Science Olympiad?
Both names use the abbreviation IESO. This page covers the International Earth Science Olympiad run by IGEO since 2007, with national teams of four. The International Environmental Science Olympiad is a separate, much newer contest run by an American organiser with its own rules.
Who can take part in IESO?
Secondary school students who are not older than 18 on 1 July of the competition year and are not yet at university. In practice they are usually in Grade 9-12, and they must be selected by their country.
How many students does each country send?
One team of four competitors, accompanied by two mentors.
What subjects does IESO cover?
Geology, geophysics, meteorology, oceanography, terrestrial astronomy and environmental science, often combined in the same question.
Where can I find IESO past papers?
IGEO publishes past IESO exams on its official website. Some national organisers, such as the Geological Society of India and the United States Earth Science Organization, also share selection or practice papers.