Culture · Science · The weather record
The Weather of 1817
Observations at Vellmar, with the level of the Ostra, fog on the river and the state of Lake Tarn at Tarnmund, as recorded by the Ministry of the Interior. Temperatures in degrees, rainfall in millimetres.
9.8°Mean of the year
752 mmRainfall
60Fog days on the Ostra
2.5 mOstra above its mark, highest
9 January 1817Lake Tarn
The months
| Month | Mean | Warmest day | Coldest night | Rain | Fog days | Frost days | Remarks |
|---|---|---|---|---|---|---|---|
| January | -1.6° | 10° | -10° | 59 mm | 6 | 28 | |
| February | -0.3° | 11° | -12° | 56 mm | 5 | 20 | |
| March | 4.0° | 14° | -6° | 68 mm | 4 | 0 | Fog on the marsh most mornings. |
| April | 9.3° | 22° | 0° | 31 mm | 3 | 0 | Dry; dust on the Marschau road. |
| May | 14.6° | 27° | 3° | 47 mm | 3 | 0 | Late frost in the Sudmark vineyards. |
| June | 17.9° | 29° | 7° | 62 mm | 4 | 0 | Dry and warm; Lake Tarn low at Tarnmund. |
| July | 20.3° | 30° | 11° | 75 mm | 0 | 0 | Thunder over the Kesselhöh on several evenings. |
| August | 20.1° | 33° | 8° | 73 mm | 0 | 0 | The Ostra fell to its summer mark. |
| September | 16.4° | 28° | 5° | 63 mm | 3 | 0 | The reed harvest was gathered in good order. |
| October | 11.7° | 23° | 3° | 69 mm | 8 | 0 | Fog on the marsh most mornings. |
| November | 7.0° | 16° | -1° | 75 mm | 12 | 0 | The Ostra carried ice at Vellmar bridge. |
| December | -2.3° | 11° | -13° | 74 mm | 12 | 31 | Hard frost on the causeway; the planks were sanded. |
Lake Tarn
The lake froze at Tarnmund on 9 January 1817, as the towns reported and bore the weight of a man by the end of the month; the ferry to the eastern shore was replaced by a marked path. The thaw is recorded on 1 March 1817.
The Ostra
The river rose to 2.5 metres above its mark at Vellmar bridge at the highest. 60 days of fog were recorded on the lower river, the ferries stopping when the far bank could not be seen.
Note
The record for 1817 was kept by the Ministry of the Interior from readings at Vellmar and the garrison at Marschau, before the Observatory at Tarnmund was established. Readings on the Osmoor beyond the Reed Line were not taken.
Warmest month, 20.3°; coldest, -2.3°. Means are of the month; the warmest day and coldest night are the extremes recorded.
Weather in the public record
- 9 January 1817, Grautal. The coldest night in 60 years is recorded at Grautal. Lake Tarn freezes to the middle. Report.
- 10 January 1817, Sudholt. A storm strips roofs in Sudholt and fells the old lime in Bridge Street. Report.
- 10 January 1817, Grautal. A storm strips roofs in Grautal and fells the old lime in Iron Way. Report.
- 11 January 1817, Wasserdorf. The coldest night in 30 years is recorded at Wasserdorf. Lake Tarn freezes to the middle. Report.
- 25 January 1817, Sudfurt. A storm strips roofs in Sudfurt and fells the old lime in Cooper Row. Report.
- 31 January 1817, Kessel. The coldest night in 60 years is recorded at Kessel. Lake Tarn freezes to the middle. Report.
- 5 February 1817, Oberbach. The Ostra rises 80 centimetres above its mark at Oberbach. Cellars in Reed Street are flooded. Report.
- 12 February 1817, Brennholt. The Ostra rises 60 centimetres above its mark at Brennholt. Cellars in Long Street are flooded. Report.
- 16 February 1817, Norrhafen. The Ostra rises 60 centimetres above its mark at Norrhafen. Cellars in Lime Square are flooded. Report.
- 3 March 1817, Berging. The coldest night in 70 years is recorded at Berging. Lake Tarn freezes to the middle. Report.
- 7 March 1817, Vellhausen. A storm strips roofs in Vellhausen and fells the old lime in Forge Walk. Report.
- 9 March 1817, Eisenheim. A storm strips roofs in Eisenheim and fells the old lime in Ostra Square. Report.
- 15 March 1817, Grauholt. The coldest night in 50 years is recorded at Grauholt. Lake Tarn freezes to the middle. Report.
- 7 April 1817, Marschau. A storm strips roofs in Marschau and fells the old lime in Star Street. Report.
- 23 April 1817, Grauburg. The Ostra rises 20 centimetres above its mark at Grauburg. Cellars in Salt Row are flooded. Report.
- 21 May 1817, Reedtal. A storm strips roofs in Reedtal and fells the old lime in Short Row. Report.
- 24 May 1817, Vellmar. The coldest night in 40 years is recorded at Vellmar. Lake Tarn freezes to the middle. Report.
- 7 June 1817, Oberholt. The coldest night in 70 years is recorded at Oberholt. Lake Tarn freezes to the middle. Report.
- 8 June 1817, Oberholt. The Ostra rises 50 centimetres above its mark at Oberholt. Cellars in Church Street are flooded. Report.
- 13 June 1817, Weinau. A storm strips roofs in Weinau and fells the old lime in High Street. Report.
- 16 June 1817, Norrwick. A storm strips roofs in Norrwick and fells the old lime in New Gate Quay. Report.
- 3 July 1817, Lindenmar. The coldest night in 80 years is recorded at Lindenmar. Lake Tarn freezes to the middle. Report.
- 11 July 1817, Tarnmund. The coldest night in 50 years is recorded at Tarnmund. Lake Tarn freezes to the middle. Report.
- 7 August 1817, Eisenheim. A storm strips roofs in Eisenheim and fells the old lime in Harbour Square. Report.
- 5 September 1817, Hollstadt. The Ostra rises 50 centimetres above its mark at Hollstadt. Cellars in Mill Row are flooded. Report.
- 8 September 1817, Sanding. The coldest night in 30 years is recorded at Sanding. Lake Tarn freezes to the middle. Report.
- 21 September 1817, Sudholt. The coldest night in 50 years is recorded at Sudholt. Lake Tarn freezes to the middle. Report.
- 4 October 1817, Grauburg. The Ostra rises 40 centimetres above its mark at Grauburg. Cellars in Bridge Quay are flooded. Report.
- 12 October 1817, Ostrabruck. The Ostra rises 40 centimetres above its mark at Ostrabruck. Cellars in Forge Gate are flooded. Report.
- 20 October 1817, Sudfurt. The Ostra rises 30 centimetres above its mark at Sudfurt. Cellars in Cooper Row are flooded. Report.