Winter timeline 2019/20

Foreword, written on 5 April 2020.

Before posting, I read through the timeline to spot errors and do some editing. I am looking back at past days with disbelief. Over most of the period covered by the timeline, life was going on normally.

According to most long-term forecasts available around October 2020, the passing winter was meant to be one of the mildest ever, however I spotted one of two predictions of harsh winter, especially January and February 2020. In late November 2019 the Polish Met Office issued a forecast of “normal” winter in January and February 2020.

30 October 2019

First frost this autumn comes 15 days later than on average, at the end of the third warmest October since records began. It needs to be noted Warsaw miraculously averted sub-zero temperatures in the first decade of October 2019 when frost was observed in most places in Poland, while the sky over the capital was shielded by clouds. This and two next frosty mornings are just an interlude in a warm autumn. The proper winter timeline commences with the incidence of first snowfall or when day-time high does not climb above freezing.

November 2019, the warmest after WW2 (average temperature 3 Celsius degrees higher than long-term average), with mere 3 days when temperature dipped for a few hours below 0C, lack of snow and sleet, could not constitute a part of winter timeline, but deserves a separate posting.

29 December 2019

The first day when temperature stayed below the point of freezing all the time (it peaked at –0.4C) marks the beginning of the winter timeline.

30 December 2019 – 31 December 2019

Late autumn (positive temperatures, gusty winds) returns. Longing for sunshine which was last witnessed on 21 December.

December 2019 was very warm. Average temperature in Warsaw was +3.3C (vs. long-term average of –0.7C) and was the third highest since records began, after December 2015 (mean temperature: +4.7C) and December 2006 (mean temperature: +4.0C) Stats:

- month-time high: +12.9C on 18 December 2019 (more than 2 Celsius degrees short of December’s record, +15.4C set on 5 December 1961)

- month-time low: –6.6C on 11 December 2019 (day-time high of +2.1C on that day precluded me from launching the winter timeline then),

- the warmest day: 18 December 2019 (daily average of +7.7C, such warm days have been observed over nearly all Decembers in recent years),

- the coldest day: 11 December 2019 (daily average of –2.2C, one of 4 days with sub-zero daily mean temperature and one of 2 days in the entire month with temperature below long-term average).

December 2019 was also snow-free (I count out 20-minute sleet on 27 December 2019 between 8:00 a.m. and 9:00 a.m. at the temperature of +1C and another such incident on 31 December 2019), it was the third snow-free December in my lifetime (after December 1987, December 2006).

Worth noting 4Q2019 was the warmest fourth quarter since records began, with average temperature of +6.93C (vs. long-term mean of +3.6C), beating 4Q2006, when temperature averaged out +6.87C.

1 January 2020 – 6 January 2020

Late autumn continues, most of the time exhibiting its gloomy and rainy look, seldom rationing out moments of sunshine. Night-time lows between –5C and +1C, day-time highs between +2C and +6C, but on all days average daily temperature is above 0C, except for 6 January when mean temperature stood at –0.1C.

7 January 2020 – 15 January 2020

Same weather pattern as in the earliest days of January, except for lack of night-time frosts and more sunshine. 9 days without frost are far cry from a record-long 22-day frost-free period in January observed in Warsaw from 1 January 2007 to 22 January 2007.

16 January 2020

Evening brings sharply falling temperature. But no, winter is not coming.

17 January 2020

–5C at the dead of night, picturesque freezing fog and hoar frost in the morning remind calendar-wise it is winter. Fog or smog and positive temperature over the day.

18 January 2020 – 24 January 2020

Temperatures between –2C and +5C, sparse sunshine, lots of fog and drizzle (but no freezing) and no trace of winter.

25 January 2020 – 26 January 2020

Close to zero, fog, freezing drizzle, damp, chilly wind. Feels like November has lasted three months now…

27 January – 28 January 2020

Colder mornings (–2C is still not cold January-wise), warmer middays, some sunshine.

29 January 2020

First snow this winter! It begins around 9 a.m. and snows, at times heavily until 4 p.m. Temperature is positive all the time, but the flurry is enough intensive to linger on the ground and to turn into slush on pavements. Again, I believe pedestrians are second-class citizens in Warsaw.

30 January 2020

The snow has melted overnight as temperature stayed at +3C. The day is rainy and windy, proving the weather has returned to a mode which cannot be named late autumn nor early spring.

31 January 2020

The last day of the month brings another assault of warmth…

January 2020 was very warm. Average temperature in Warsaw was +2.5C (vs. long-term average of –1.9C). It ranked as third-warmest January (at the par with January 1921) after January 2007 (+3.7C) and January 1983 (+3.2C). Stats:

- month-time high: +9.9C on 15 January 2020 (4 Celsius degrees short of the record-warm +13.8C measured on 12 January 1993),

- month-time low: –4.7C on 3 January 2020 (at the par with so far the highest January’s low of –4.7C recorded on 21 January 1983),

- the warmest day: 10 January 2020 (daily average of +7.3C, which is remarkably high as for statistically the coldest month of the year),

- the coldest day: 17 January 2019 (daily average of –0.7C, which is higher than long-term average for the entire month, one of 3 days with sub-zero average daily temperature over the month, remarkably there was no day with top temperature below freezing),

- number of days with snow cover: 1,

- the highest snow depth: no idea how many centimetres on 29 January 2020, since the official weather report for that day does not show any snow cover, which is a blatant distortion!

I have learnt the reason is that they measure snow cover once in 24 hours, at 6:00 a.m. On 29 January at that time the snow was not falling, by the same hour on the next day it melted. Fortunately, ample evidence is saved for posterity to prove the current record of the latest first snow has been just beaten.

1 February 2020

Believe it or not, but the first scent of spring is in the air. Windy, at times rainy, at times sunny and abnormally warm (around +12C in the afternoon) as for early February.

2 February 2020

Not as warm as yesterday, gone is the scent of spring. Windy, with a summer-like squall.

3 February 2020 – 4 February 2020

Temperature drifting towards range typical for that time of year. Still bleak, cloudy and rainy.

5 February 2020 – 7 February 2020

What was meant to be a “cold outbreak” or an “arctic blast” turns out to bring night-time frost, chilly wind and clear blue skies. Nevertheless temperatures remain above average for this time of year.

8 February 2020 – 9 February 2020

Clear blue skies, light frost at nights, day-time highs above +5C. At the same time large swathes of the Balkan peninsula and eastern Europe are under deep snow…

10 February 2020

Holy shit. Hurricane Ciara brings howling wind, temperature above +10C, heavy rain, thunderstorm and… hail.

11 February 2020 – 13 February 2020

Cold, gloomy pre-spring, with no sunshine, gusty wind, rain, drizzle, sleet or snow, yet instantly melting.

14 February 2020 – 15 February 2020

Snow falls and lingers for a short while, then turns into drizzle. Still too little to call it even a touch of winter.

16 February 2020

After a frosty morning… Double-digit temperatures and winds return. Rain in the evening.

17 February 2020

Waking up to double-digit temperature in the morning is an absolute anomaly in February. Then in the afternoon temperature shoots up to nearly +15C. Feels like early April, that specific scent of winter giving way to spring is in the air.

18 February 2020 – 20 February 2020

Colder, which means between 0C and 10C, all sorts of weather typical for pre-spring.

21 February 2020

A touch of winter brings sleet, then rain and temperature below 5C (yet still above 0C).

22 February 2020

Precipitation from yesterday has frozen over as temperature around dawn plunged near 0C. The ensues a bright, rather sunny, yet windy day. In the evening temperature exceeds +10C.

23 February 2020 – 26 February 2020

Pre-spring shows its gloomy face. Cloudy, rainy (though dried-up soil longs for water) and windy. Needless to say temperatures stay above freezing.

27 February 2020

It snows, several times a day, sometimes heavily, yet every time the snow melts.

28 February 2020 – 29 February 2020

Frosty mornings and chilly afternoons bring mean temperature for the first time since late December close to long-term mean for the period.

February 2020 was anomalously warm. Average temperature in Warsaw was +3.9C (vs. long-term average of –1.0C). It ranked as second-warmest, after February 1990 (mean temperature: +4.6C) and at the par with February 1989. Stats:

- month-time high: +14.3C on 17 February 2020 (still 3 degrees short of all-time record set on 25 February 1990),

- month-time low: –3.9C on 8 February 2020 (thus record of maximum February’s low set in February 1990 was broken by 0.1C degree),

- the warmest day: 17 February 2020 (daily average of +10.4C, in total there were 9 days this month with double-digit temperatures, less than in February 1990 when temperature topped above +10C on 13 days),

- the coldest day: 7 February 2020 (daily average of –0.3C, just like in January, the coldest day was above the long-term average for the entire month),

- number of days with snow cover: 0.

1 March 2020 – 9 March 2020

No signs of winter, including lack of night-time frosts (except for 5 March, when temperature before dawn dropped below –2C, and 9 March).

10 March 2020 – 12 March 2020

A period of double-digit daytime highs, which do not necessarily mean it is sunny. It often rains, yet the rain is indispensable for vegetation and for farmers.

For this occasion some statistics when in past ten years temperature exceeded +15C for the first time (day-time highs in brackets):

4 March 2019 (+15.4C), then +17.2C on 17 March 2019,

11 March 2018 (+15.4C),

5 March 2017 (+15.8C),

28 March 2016 (+15.1C),

24 March 2015 (+16.0C) and close to +20C on three consecutive days,

21 March 2014 (whopping +22.4C),

13 April 2013 (+15.7C) – this was the coldest March in my lifetime,

17 March 2012 (+20.0C),

13 March 2011 (+15.6C),

20 March 2010 (+17.5C),

Which means on average temperature should rise above +15C on 19 March and day-time highs above +15C in the second decade of March (7 days earlier in 2020) are nothing unusual, just like snow and frost (like the one we witnessed in 2010, 2013 or 2018).

13 March 2020

Balmy period comes to an end. Day-time high is +8C, but forecasters warn of winter incident ahead.

14 March 2020

Snow showers several times a day, yet at temperature of +3C hard to expect white landscapes.

15 March 2020

The coldest morning in the period covered by winter timeline: –8C before dawn. Shortly after sunrise temperature soars to reach nearly double-digits in the afternoon.

16 March 2020 – 20 March 2020

Cold mornings, balmy (above +10C) afternoons. Large temperature fluctuations help the invisible enemy.

21 March 2020

A chilly day with intermittent flurry. Snow melts instantly for the same reason as each day this… cold season.

22 March 2020 – 25 March 2020

A little arctic blast. Pre-dawn lows near –5C, afternoon highs well below +10C. Chill compensated by continual sunshine. Cold keeps people indoors. For the first time since many weeks temperatures decline below long-term averages for the period.

26 March 2020 – 28 March 2020

Sunny, warm, close to zero before sunrise. Considerably above +10C in afternoons. Gusty easterly winds take the gloss off brilliant sunshine.

29 March 2020

Day-time high of +13C is higher than foreseen. As the sunset approaches, the weather breaks – temperature drops, finally some rain falls on dry soil. The last gasp of winter is due in a few hours. A nuisance today is a record-bad air quality in Warsaw. I have always cherished the day when clocks go forward; this year my joy is muffled.

30 March 2020

In many places in Poland morning greets with snow. In Warsaw morning brings just morning frost. Several snow showers over the day, white powder even lingers for a while. Day-time high of mere +3C.

31 March 2020

I hoped to a sight of snow fallen overnight. It indeed fell near Piaseczno, but in Warsaw only frost (quite sharp, –5C) was observed. Chilly, yet sunny

March 2020 was slightly warm. Average temperature in Warsaw was +4.9C (vs. long-term average of +2.8C). Quite warm, yet colder than in 2014 (+7.0C), 2017 (+6.2C), 2019 (+6.0C), 2015 (+5.5C). Stats:

- month-time high: +17.4C on 28 March 2020 (a whiff of spring which could have contributed to spreading the disease),

- month-time low: –7.9C on 15 March 2020 (which was the coldest morning of the entire winter),

- the warmest day: 18 March 2020 (daily average of +10.3C),

- the coldest day: 30 March 2020 (daily average of –0.2C, one of two days with sub-zero average temperature, plus it was some five Celsius degrees colder than long-term average in last days of March),

- number of days with snow cover: 0.

1 April 2020

The frosty morning brings the warmest winter ever to an end. Each next day is foreseen to be warmer than previous. In the coming days we should see +20C for the first time this year.

The entire 2019/20 winter (defined as December, January and February) was the warmest since records began in Warsaw. With average temperature of +3.2C it beat the previous record of 1989/90 winter by 0.9 Celsius degree.

All records of mild winter were broken:

There was only 1 day (29 January 2020) with snow cover, it beat the record set in 1988/89 winter when snow was lying on 15 days (22 November 1988 – 24 November 1988, 4 December 1988, 8 December 1988 – 11 December 1988, 15 December 1988 – 18 December 1988, 21 December 1988, 8 January 1989, 2 April 1989)

Depth of snow cover on 29 January 2020 was unknown (since measurements are taken once a day, at 6:00 a.m.), but definitely was lower than no more than 4 centimetres during 2007/08 winter (measured on 7 January 2008, on 18 February 2008 and on 27 March 2008)

The highest minimum temperature was –7.9C (15 March 2020), it narrowly beat the record from 1974/75 winter, when temperature fell no lower than –8.0C on 17 February 1975.