2023 began in a way that perfectly foreshadowed the rest of the year. On the very first temperature measurement of the year, the Netherlands recorded an unprecedented January temperature of 15.6°C during a rainy ‘winter’ night. This was not only record-breaking for the month of January, but also 2.4°C higher than the previous New Year’s Day record set just a year earlier. This proved to be merely the beginning. The year 2023 turned out to be the warmest and wettest on record, which is in line with current climatological trends.
The Netherland’s main weather station in De Bilt recorded an average temperature of 11.8°C in 2023. This is above the previous highs of 11.7°C observed in both 2014 and 2020. It is also well above the climatological norm for the period 1991-2020: 10.6°C.
In terms of precipitation, 2023 set a new record as the wettest year in the Netherlands. The national average, calculated from 13 rain gauges across the country, reached 1153 mm – well above the previous record of 1109 mm set in 1998. The rain gauge in Purmerend recorded the highest local annual rainfall with 1435 mm (previous record: 1387 mm in Heemstede in 1915). De Bilt’s weather station marked its second wettest year, recording about 1180 mm (record: 1235 mm in 1998).
Nationally, it was the wettest year on record. The national precipitation is an average measured over 13 rain gauges.
The Bilt measured the 2nd rainiest year on record.
2023: A sunny year despite the rain, reflecting the ‘new climate’
With 1913 hours of sunshine, well above the climatological norm of 1718 hours, 2023 was the 7th sunniest year on record. The sunniest year on record was set just one year earlier, in 2022. During this exceptional year, an extraordinary 2233 hours of sunshine was recorded.
The abundant sunshine in 2023 may seem paradoxical in such a rainy year. Yet, this combination of high temperatures, large amounts of rain, and lots of sunshine aligns closely with the emerging patterns of the ‘new climate’. In the Netherlands, trends are moving towards higher temperatures and increased precipitation. The increase in precipitation is mostly due to higher rainfall events, rather than increased rainfall duration. Increases in temperature and precipitation are accompanied by sunnier conditions.
While one could intuitively think that increased rainfall would counteract drought, this isn’t always the case. The increased sunshine and higher temperatures also contribute to greater evaporation, which in turn can lead to drought conditions.
When soils are dry, their capacity to absorb water is reduced. Consequently, much of the rainfall results in runoff rather than infiltration – especially during heavy downpours. This means that, even when lots of rain fall, drought conditions can persist, as the dry soil is unable to effectively absorb the water.
The figure above shows the ‘climatological barcode’ of the Netherlands. Upward trends in temperature, precipitation, and sunshine can be seen. This year therefore alighns clearly with the ‘new climate’. Figure by Karin van der Wiel / KNMI, adopted from this article.
Drought in a year of abundant rain
With the current situation, where soils are completely saturated and rivers are experiencing extremely high water levels, it’s hard to imagine that earlier in the year, the Netherlands faced quite the opposite challenge: droughts. During May and June, the main weather station in De Bilt recorded an unprecedentedly long period without measurable rain. For 39 consecutive days, no significant rainfall was recorded. During this period, various drought-related issues emerged.
Moderate maximum temperatures in a record warm year
While 2023 was record-warm overall, the year’s highest temperatures were not exceptionally high. The highest temperature recorded in De Bilt was 32.2°C, which is notably lower than the 37.5°C record set in 2019. This year’s high average temperature can be explained by a consistently higher ‘baseline’ temperature throughout the year. For instance, the average daily minimum temperatures this year were the highest on record. The average daily maximum temperatures were slightly below record levels. Additionally, 2023 recorded the second-highest number of ‘warm days’—days when maximum temperatures exceeded 20.0°C—second only to the record set in 2018.
The figure above shows the average daily maximum temperature, which was just below record high levels.
The figure above shows the average daily minimum temperature, which was record high this year in the Netherlands.
The figure above shows the yearly maximum temperature, which was far from record levels, despite the record high average temperature this year in the Netherlands. Nevertheless, extremely high maximum temperatures are becoming more frequent.
Year ends in fashion
After kicking off the year with record warmth, 2023 closed in a similar fashion. The last days of the year, especially the nights, were warm for this time of the year, with temperatures several degrees above climatological norms. Fittingly, intense rainshowers occurred on the final day, accompanied by strong winds and even thunder. All in all, a fitting closure to a record warm and record wet year.
