Climate of Plovdiv, Bulgaria

By Kiril Donov, M.Sc. Tropical and Subtropical Agriculture

When I mean cold hardy palms, I mean palms able to survive the continental winter. Yes, I know it is cold in northern Italy, but cold itself means just a bad feeling to our skin. Below are full details about the continental winter in Plovdiv, southern Europe. That's winter, isn't it? It could compare to the winters much further north from Bulgaria.

Plovdiv, Bulgaria is located in the Thrace valley at 160 meters above the sea level. The northern latitude is 42' 09'' . It is 160 km away from the capital Sofia and 280 km away by road to Bourgas on the Black Sea coast. Just 180 km south from Plovdiv is the Aegean Sea, but unfortunately all this distance belongs to the largest mountain in Bulgaria - Rhodopa mountain. That is why the Mediterranean influence to the climate of Bulgaria is much decreased. It's normal to see snow in April, even in May (very rare). Note, that in Greece snow is seen once a decade or never, and only in December or January. 

Photo taken in Plovdiv in late April 2002.

The valley is surrounded by high mountains and in clear cold winter nights with snow cover a temperature inversion is observed. In Assenovgrad, which is only 12 km away from Plovdiv, but at 80m higher altitude the extreme minimums are always higher. For example in 1977 in Plovdiv the absolute minimum was -21,2°C (-6,2°F) and in Assenovgrad it was -13,0°C (8,6°F). In Assenovgrad we see old fig trees but in Plovdiv they die to the ground regularly.

As you can see on the picture, north of Plovdiv is the Balkan mountain which crosses the Balkan peninsula from west to east. In summer Plovdiv is often the hottest point of Bulgaria and Europe. During the last decade the global warming caused very hot summers , 35-45°C (95-113°F). This, combined with drought makes the summer in Plovdiv area very difficult for the plants. Palms usually get leaf damages in summer.

You will find below some details about the climate of Plovdiv. Source: "Agro climatic atlas of Bulgaria", "Annual meteorological book" and "Climate resources of Bulgaria", all issued by the National institute of hydrology and meteorology.

1. Temperature sum for the period with temp. above 10°C (50°F) - 4200°C (7232°F);
2. Duration of the sunshine for the period with temp. above 10°C (50°F)- 1750 hours;
3. Average annual sum of precipitation - 550 mm (21,65 inches);
4. Average first date of the period with constant keeping the average daily temperatures above 5°C (41°F) - March, 5th;
5. Average final date of the period with constant keeping the average daily temperatures above 5°C (41°F) - November, 28th;
6. Average duration of the period with constant keeping the average daily temperatures above 5°C (41°F) - 260 days;
7. Average date of the last spring frost - April, 15th;
8. Average date of the first autumn frost - November 1st;
9. Average duration of the frost free period - 202 days;
10. Average air temperature for the warmest month - 23°C (73,4°F);
11. Average number of days with temperatures higher than 30°C (86°F) - 52 days;
12. Average first date of the period with constant keeping the average daily soil temperatures above 5°C (41°F) - February, 28th;
13. Average air temperature for the coldest month, January - +0,2°C (32,4°F);
14. Average number of days with average daily temperature below 0°C (32°F) - 35 days;
15. Average of the absolute annual minimum temperatures - (-16,4°C (2,5°F); (ZONE 7a)
16. Average date of the first snow cover - December 11th;
17. Earliest date of the first snow cover - November 14th;
18. Latest date of the first snow cover - February 8th;
19. Average date of the last snow cover - March 11th;
20. Earliest date of the last snow cover - December 8th;
21. Latest date of the last snow cover - April 16th;
22. Average number of days with snow cover - 30 days;
23. Absolute minimum temperature ever recorded - (-31,5°C (-24,7°F) in 1942
 

27. Absolute minimum temperatures for January -31,5°C (-24,7°F), for February -29,1°C (-20,4°F), for March -17,5°C (0,5°F), for April -4,0°C (24,8°F), for May -0,3°C (31,5°F), for October -5,8°C (21,6°F), for November -9,1°C (15,6°F), for December -21,5°C (-6,7°F);
28. The probability to happen temperatures below -14,3°C (6,3°F) is 40% each year. For temperatures below -27,5°C (-17,5°F) the probability is 5%
In 1993 in Plovdiv a temperature of -27,3°C (-17,1°F) was recorded;
In 2001 the extreme minimum temperature was -21,5°C (-6,7°F), recorded at the Polar Palms Nursery. In the city of Plovdiv the temperature was even 1degree C lower!