A new Yorkshire Dirt Index 2026 has revealed that winter is the dirtiest season for workplaces across the region, driven by muddy commutes, wet weather, gritted pavements and peak office footfall.
Released by the York and Leeds-based commercial cleaning Smart Cleaning, the index analyses seasonal cleanliness patterns in offices, coworking spaces and commercial buildings across Leeds, York and the wider Yorkshire region.
It combines real-world cleaning data with local weather and workplace behaviour trends.
Ben Hirst, owner of Smart Cleaning, said: “Workplace dirt follows clear seasonal patterns, and winter is by far the most challenging time of year.
“Muddy commutes, wet entrances and high footfall combine to create constant cleaning pressure across Yorkshire offices.”
The Five Dirt Factors
- Rainfall & Mud Risk — Rain causes wet foyers, salt from icy roads makes its way inside and muddy ground gets tracked indoors
- Pollen Levels — Tree and grass pollen settles on desks, vents and carpets causing hay fever, while bins fill with hankies.
- Insects & Pests — Flies, wasps and spiders leave webs and their swatted bodies in corners and windowsills, while birds who target them leave droppings on windows
- Footfall Levels — Occupancy, commuting patterns and busy periods can impact how dirty offices get
- Human Behaviour — Spills, desk clutter and waste build-up change seasonally leading to different dirt levels.
Seasonal shifts in office cleanliness
The findings show clear seasonal differences in workplace mess, with summer ranked as the cleanest period and winter creating the highest cleaning demand.
Yorkshire Dirt Index – Seasonal Rankings
- Summer: Cleanest (Dirt Score: 4/10)
- Spring: Mixed conditions (6/10)
- Autumn: High dirt season (8/10)
- Winter: Dirtiest (10/10)
According to the index, winter conditions consistently create the most persistent workplace dirt, with mud, grit and slush tracked deep into carpets, alongside increased waste and surface contamination during flu season.
Spring 2025 was heavily impacted by unusually high pollen levels, which settled on desks, vents and equipment despite dry weather, while autumn saw rising dirt levels as offices refilled and rainfall increased following a dry start to the year.
Summer remained the cleanest season overall, supported by lower footfall and drier conditions, although large regional events such as the Great Yorkshire Show, York Races and Leeds Pride caused temporary spikes in workplace mess.
Find out more about the Yorkshire Dirt Index 2026.
