40. Tourism seasonality glossary: arrivals, nights spent, length of stay, occupancy, Gini

Tourism reports, funding calls and statistical releases are full of words that seem obvious and are not: an "arrival" is not a tourist, "nights spent" are not people, and "seasonally adjusted" data have had seasonality removed. This glossary collects the terms of tourism seasonality with their official international definitions (United Nations, UN Tourism, Eurostat, OECD), the names used by some national offices, and an example of what can go wrong.

Who travels: visitors, tourists, same-day visitors

Visitor

A traveller taking a trip to a main destination outside their usual environment, for less than a year, for any main purpose (business, leisure or other personal purpose) other than to be employed by a resident entity in the place visited (IRTS 2008, paragraph 2.9). Tourism is the activity of visitors.

Watch out: seasonal workers who move to a resort for the summer are not visitors, even though they arrive in high season.

Tourist and same-day visitor (overnight visitor, excursionist)

A visitor is a tourist (overnight visitor) if the trip includes an overnight stay, and a same-day visitor (excursionist) otherwise (IRTS 2008, paragraph 2.13).

Watch out: accommodation statistics only count tourists who sleep in those establishments. Most of the audience at a one-day local festival are same-day visitors, who do not appear there.

Usual environment

The geographical area, not necessarily contiguous, within which a person conducts their regular life routines (IRTS 2008, paragraph 2.21). It keeps routine trips, such as commuting to work or school, out of visitor counts.

Domestic, inbound and outbound tourism

Relative to a reference country: domestic tourism is residents travelling within the country; inbound is non-residents travelling in the country; outbound is residents travelling abroad. Domestic plus inbound is internal tourism; domestic plus outbound is national tourism; inbound plus outbound is international tourism (IRTS 2008, paragraphs 2.39 and 2.40).

Example: Eurostat tables show the same split as “Domestic country” and “Foreign country”, i.e. residents and non-residents (table tour_occ_nim).

What is counted in tourist accommodation

Tourist accommodation establishment

In European statistics this covers hotels and similar accommodation, holiday and other short-stay accommodation, and camping grounds and parks for recreational vehicles and trailers (NACE codes 55.1-55.3 in Eurostat table tour_occ_nim). Italy's ISTAT splits them into hotel and non-hotel establishments, the latter including campsites, holiday villages, farm stays, hostels, bed and breakfasts and private rentals (ISTAT glossary, Q1 2026 release, in Italian).

Arrivals

A tourist, resident or non-resident and of any age, who arrives at a tourist accommodation establishment (Eurostat). ISTAT puts it as people who checked in at an accommodation establishment in the period (ISTAT).

Watch out: someone who changes hotel during a trip counts as two arrivals. Arrivals count check-ins, not different people.

Nights spent (called “presenze” in Italy)

Each night a guest, resident or non-resident, actually spends in a tourist accommodation establishment (Eurostat).

Watch out: a family of four staying three nights generates 12 nights spent and 4 arrivals. The Italian word “presenze” sounds like “people present” but is a count of nights.

Average length of stay

Nights spent divided by arrivals in the same period (ISTAT). In Italy in the first quarter of 2026 it was 3.12 nights: 3.53 for international guests and 2.74 for residents (ISTAT, Q1 2026).

Bed places

The number of people who can stay overnight in the beds set up in the establishment, ignoring extra beds added on request: a single bed is one bed place, a double bed two; a camping pitch counts as four bed places if the real number is not known (Eurostat).

Net occupancy rate of bed places and of bedrooms

For beds: nights spent in the period divided by bed places on offer, excluding extra beds and net of seasonal and other temporary closures, times 100. For bedrooms: bedrooms used divided by bedrooms available net of closures, times 100. Because extra beds are excluded, the bed-place rate can exceed 100% (Eurostat).

Gross bed-place utilisation

A convenience measure when you do not know how many days establishments were closed: nights in the month divided by (bed places × days in the month). It is not Eurostat's net rate.

Example: 40 bed places, a 31-day January, 186 nights: 186 / (40 × 31) = 15%. If the property was closed for 16 days, the net rate over the 15 open days is 186 / (40 × 15) = 31%. Gross utilisation understates how full open properties are, but shows clearly how much capacity sits idle in winter.

Measuring seasonality

Tourism seasonality

Variations in visitor arrivals on a regular time horizon and in regular frequencies; the unequal distribution of tourist activity is generally considered one of the major challenges for tourism businesses and local communities (UN Tourism, MST indicator proposals, September 2023). UN Tourism proposes measuring it as the percentage of inbound visitors arriving in the peak months or peak quarter.

Peak-month share (share of the top 2 months)

The percentage of the year's nights spent in the two busiest months, usually July and August in Europe (Eurostat, seasonality at regional level). With twelve equal months it is 16.7%.

Example: in 2024 Calabria (Italy) had 58.8% and Lazio 21% (Eurostat).

Seasonality Gini coefficient

The difference between the cumulative share of monthly nights spent, with months ranked from lowest to peak, and the uniform distribution you would see without seasonality (Eurostat). It is 0 if all months weigh the same; with twelve months the maximum is 11/12. Formula: G = Σ (2i - 13) × x_i / (12 × Σ x), with months sorted from smallest to largest.

Example: for 2025 Eurostat reports 0.25 for the European Union and 0.59 for Croatia (Eurostat).

To calculate it on your own twelve monthly values, together with the peak-month share, use the seasonality of your data tool.

Peak-to-average ratio

The busiest month divided by the monthly average. Not an official indicator, but it comes from the same data and is the easiest to explain: a value of 2 means the peak month is worth two normal months.

Peak season, low season, shoulder season

There is no official statistical threshold. UN Tourism refers to peak, shoulder and low seasons without fixing their boundaries (UN Tourism, 2023). A practical rule, stated as such: peak season is the months above the monthly average; low season the weakest months of the year; shoulder season the months below average but not at the bottom, usually those next to the peak.

Watch out: the shoulder season is the most realistic target for off-season events, because accommodation and services are often still open.

Reducing seasonality (spreading demand, off-season tourism)

The set of actions that spread tourist flows less tightly across months and places. The OECD describes destinations promoting the “geographic and seasonal spread of tourists” (OECD, Tourism Trends and Policies 2024).

Watch out: “deseasonalisation” is rare in English and mostly statistical; when searching for sources use “tourism seasonality”, “off-season” or “spreading tourism demand”.

Seasonal adjustment (seasonally adjusted data)

A statistical method for removing the effects of recurring seasonal influences from a time series, to show the underlying trend more clearly (Eurostat).

Watch out: seasonally adjusted figures have lost exactly the pattern you want to study. To measure the summer peak you need unadjusted data.

Reading the data without falling into traps

Break in series (discontinuity)

A change in definition, coverage or method that makes one year not comparable with earlier ones. Example: since January 2025 Italian data on holiday dwellings also include those managed on a non-business basis, and ISTAT warns that this creates a discontinuity in the other-accommodation series and in the totals (ISTAT, monthly dataflow description).

Short-term rentals

Private homes rented out for short tourist stays. Countries record them differently. In Italy they appear as private rentals managed on a business or non-business basis; since January 2026 ISTAT's flash statistics also include category C2 “other private accommodation”, with year-on-year changes calculated on a like-for-like basis (ISTAT, Q1 2026, in Italian). Read the methodological notes before comparing countries.

Provisional data

Figures published before the survey closes, with an estimate for missing or late responses, which may change (ISTAT, methodological note). ISTAT tables flag them with “p”; other offices use similar markers.

NUTS 2 regions

Regions in the EU's statistical classification of territorial units. Eurostat publishes monthly nights by NUTS 2 region (Eurostat), which makes regions in different countries comparable.

Climate normal

The average of a climate variable (temperature, rainfall) over a 30-year period; the current standard reference period is 1991-2020 (World Meteorological Organization, 2021). It helps choose a likely month for an outdoor event; it does not forecast the weather on a given day.

Events and destination management

Event tourism

Planned events (festivals, fairs, races, conferences) seen as a reason to travel. The OECD lists events and festivals among the ways mountain and coastal destinations try to extend their season (OECD, 2024).

MICE (meetings, incentives, conferences and exhibitions)

Business tourism. According to the OECD, many destinations invest in it partly to tackle seasonality (OECD, 2024).

DMO (destination management organisation)

The body that coordinates the management and promotion of a destination. The OECD notes that DMOs promote the seasonal and geographic spread of tourists, often with limited resources (OECD, 2024).

What this glossary does not include

There are no invented thresholds ("a Gini above X is bad") and no "good" or "bad" values: they depend on what a place offers. There are no event impact indicators, which need a method with a stated comparison. For the practical use of the measures read the guide to measuring seasonality; for a national case with data, Italy compared with Europe and Japan; for organizers, the off-season event guide.

Sources

All sources were consulted on 1 October 2026. Calculations on Eurostat and Japan Tourism Agency data are by the Play the Event editorial team, using the method described in the text.

1. International Recommendations for Tourism Statistics 2008 - United Nations and UN Tourism (UNWTO), 2010. Consulted on 1 October 2026.
2. Measuring the Sustainability of Tourism (MST): Proposals for a set of indicators - UN Tourism (then UNWTO), 2023 (September). Consulted on 1 October 2026.
3. Seasonality in the tourist accommodation sector - Eurostat, Statistics Explained, 2026 (data extracted May 2026). Consulted on 1 October 2026.
4. Tourism statistics - seasonality at regional level - Eurostat, Statistics Explained, 2025 (2024 data, extracted November 2025). Consulted on 1 October 2026.
5. Nights spent at tourist accommodation establishments - monthly data (tour_occ_nim) - Eurostat, updated 1 October 2026. Consulted on 1 October 2026.
6. Glossary: Nights spent - Eurostat, Statistics Explained, consulted 2026. Consulted on 1 October 2026.
7. Glossary: Arrival of tourist at a tourist accommodation establishment - Eurostat, Statistics Explained, consulted 2026. Consulted on 1 October 2026.
8. Glossary: Bed places - Eurostat, Statistics Explained, consulted 2026. Consulted on 1 October 2026.
9. Glossary: Net occupancy rate - Eurostat, Statistics Explained, consulted 2026. Consulted on 1 October 2026.
10. Glossary: Seasonal adjustment - Eurostat, Statistics Explained, consulted 2026. Consulted on 1 October 2026.
11. Flussi turistici - I trimestre 2026 - ISTAT (Italian National Institute of Statistics), 2026 (26 May). Consulted on 1 October 2026.
12. Movimento dei clienti negli esercizi ricettivi per tipo di esercizio - mensili (dataflow 122_54_DF_DCSC_TUR_3, descrizione) - ISTAT (Italian National Institute of Statistics), consulted 2026. Consulted on 1 October 2026.
13. OECD Tourism Trends and Policies 2024 - OECD, 2024. Consulted on 1 October 2026.
14. Updated 30-year reference period reflects changing climate - World Meteorological Organization (WMO), 2021 (5 May). Consulted on 1 October 2026.