Climate of Irad

The climate of Irad is continental, with hot summers, cold winters and low, irregular precipitation over most of the country. The northern plains are semi-arid or arid (Köppen BSk and BWk), the Talas valley is semi-arid, the river flats of the lower Naryn at the edge of the Fergana Valley have a warmer climate with dry summers (Dsa), and the Talas Alatau, Chatkal and Fergana ranges pass from humid continental conditions on their middle slopes to an alpine climate on the highest ridges.^[1] Because Irad lies far from any ocean, its weather is dominated in winter by cold air from the Siberian anticyclone and in spring and early summer by moist westerly air that drops most of its moisture on the mountains.^[2]

Most Iradis live in irrigated valleys whose farms depend on snow and glacier melt from the mountains, and the climate shapes the country's agriculture, its water politics and its transport. Spring brings mudflows and floods, summer brings heat, dust and the risk of drought and of outburst floods from glacial lakes, and winter brings snow that closes the mountain passes. Glacier retreat and a run of dry years since 2008 have made water supply a recurring subject of dispute between the Irad Special Economic Zone (ISEZ), the Autonomous Tribal Regions (ATR) and Irad's neighbors (see Glacier retreat in Irad).^[3]

Climate types and regions

Temperature falls and precipitation rises with altitude, so that the climate changes more over a few tens of kilometers between a valley floor and the crest above it than across hundreds of kilometers of plain.^[1]

Northern plains

The Betpak-Dala, the Moiynkum sands and the Kyzylkum Fringe are the driest part of Irad. Annual precipitation is generally below 180 mm (7 in), summer temperatures often exceed 40 °C (104 °F), and cold waves in winter bring temperatures below −25 °C (−13 °F), although the snow cover is usually thin. Most rain falls in spring, when it brings a short season of ephemeral grasses and tulips to the desert pastures.^[4]

Chu lowlands

Nurzhan, at 470 m (1,540 ft) on the lower Chu, has a cold semi-arid climate (BSk) with large seasonal swings. July highs average 34 °C (93 °F) and the January mean is −10.5 °C (13.1 °F); annual precipitation averages about 270 mm (10.6 in), most of it in spring. Summer dust storms are common, and outbreaks of Arctic air occasionally bring temperatures below −25 °C. Hailstorms that build over the mountains to the south are the main summer hazard for the farms of the lowlands, and since 2008 a weather radar of the ISEZ hydrometeorological service on the hill above Kök-Döbö has tracked them.^[2][5] In winter, temperature inversions over the flat plain trap smoke from the city's heating plants, and air quality in Nurzhan is at its worst during the heating season, from mid-October to mid-April.^[6]

Talas valley

Talas, at about 1,250 m (4,100 ft), has a continental, semi-arid climate (BSk). July highs average about 29–30 °C (84–86 °F), occasionally exceeding 38 °C (100 °F), and January lows average about −12 °C (10 °F), with cold winds from the Siberian anticyclone. Annual precipitation is about 300 mm (12 in), with a maximum in April and May and a dry late summer.^[7] The valley narrows and rises toward the east, and the upper valley around Orto-Ayyl has longer, snowier winters than the city. In the lower valley, around Kyzyl-Adyr, summers are hotter and the irrigation canals run short in July and August in dry years.^[8]

Toktogul basin and the lower Naryn

The Toktogul basin is sheltered by mountains on all sides and has milder winters than the Talas valley, with hot, dry summers. Below the dam, the Naryn gorge and the river flats around Iyık Janyl and Tash-Kömür have a climate closer to that of the Fergana Valley than to that of the north: at Iyık Janyl (about 650 m) July highs average about 34 °C (93 °F) and January lows about −5 °C (23 °F), and annual precipitation is about 450 mm (18 in), most of it as spring rain. Snow seldom lies for long in the towns but closes the high pastures above them from December to March.^[9]

Mountains

Precipitation increases with altitude and toward the southwest. Moist westerly air brings up to 900–1,000 mm a year to the slopes facing the Fergana Valley, where it supports the walnut-fruit forests of Arslanbob, while the northern slopes above the Talas valley are much drier.^[1] In the mountains precipitation peaks in spring and early summer, often as afternoon storms. On the Aksay Plateau, at 3,000–3,600 m, the ground is normally free of snow only from June to September, night frosts occur even in July, and snow can fall in any month.^[10] The high pastures in general are open only from about June to September.

Seasons

• Winter (December to February) is cold and, on the plains, mostly dry and clear under the Siberian high. Snow and avalanches close most mountain passes from November to April. The Fergana Gateway on State Route 1 is shut for about 20 days in an average winter, when Iradiya's flight between Talas and Tash-Kömür is the only link between the two parts of the ISEZ, and the road over the Kök-Bel Pass is often closed: in early 2020 drifts closed it for four days, and traffic was sent round by the lowland road.^[11] On the tribal side, avalanches can cut off valley villages for weeks; in February and March 2012 Kara-Jylga, north of the Toktogul Reservoir, was reached only by pack horses for five weeks.^[12] Herders fear jut, an ice crust or deep snow that seals off the winter pasture and can kill large numbers of livestock.^[1]
• Spring (March to May) is the wettest season in most of Irad. Rapid snowmelt and thunderstorms send floods and mudflows (sel) down dry washes in the foothills: in April 1998 a torrent in the Kuru-Say cut the Trans-Talas Highway west of Kyzyl-Adyr, in May 2005 a mudflow down the Tuura-Say buried orchards on the Fergana rim, and in May 2016 a flash flood in the Kök-Moinok canyons destroyed houses in the Karatau hamlet of Tar-Say.^[13]
• Summer (June to August) is hot and dry in the valleys and on the plains, and the rivers fed by snow and glacier melt run highest between May and July. In late summer, after weeks of hot weather, moraine-dammed glacial lakes in the Talas Alatau can burst: the lake at the head of the Köl-Sai broke through its moraine on 23 July 2012, and on the night of 22 July 2016 the moraine of Muz-Köl, at the head of the Muz-Suu, partly failed and the flood damaged houses in Tash-Bulak. Neither flood caused deaths.^[14]
• Autumn (September to November) is dry and settled on the plains, with the first snow on the passes in October or November. The Toktogul Reservoir is fullest at the start of autumn, after the summer melt has been stored, and lowest in early spring.^[15]

Climate data

The table compares the main weather stations of the ISEZ hydrometeorological service.^[2][7][9]

Monthly figures for Talas, including records since 1936, are given in the article on the city. The service also keeps mountain stations, such as the Kenkol Mountain Meteorological Post, automated since 2011, whose snow data are used for avalanche warnings and runoff forecasts, and its glacier and lake measurements are made with the Manas Peak Glaciological Observatory.^[16]

Droughts and water

Because the irrigated valleys depend on rivers that rise in the mountains, a dry winter or a hot summer quickly becomes a water shortage. The year 2008 brought the lowest level on record in the Toktogul Reservoir and rolling power cuts through the winter of 2008–09, which led to the 2009 protocol that brought the reservoir and dam into the ISEZ.^[15] In the drought of 2021 the flow of the Talas at the Kazakh border gauge fell to about half its mean in August, and Kazakhstan complained that it had received less than its share; the dispute was settled by counting releases from the Kyzyl-Adyr Reservoir. In 2023 the Toktogul Reservoir fell close to its minimum reserve, the authorities made an extra release in August after Uzbek protests, and power exports were cut the following winter.^[3] In both years the Chu Valley Irrigation Inspectorate cut the water quotas of large users in the lower Chu, and the textile combine Zhetysu Industrial Textiles reduced its shifts.^[17]

Glacier melt supplies about 30–40 percent of the August flow of the high tributaries of the Talas. Glaciologists expect meltwater to keep rising until the 2030s or 2040s and then to decline, and some Chatkal catchments may already have passed that peak.^[3] The ISEZ has responded with the Irrigation Modernization Programme, begun in 2018, for lining canals, laser leveling and drip irrigation, and with Executive Directive 2022/14, which requires dry-year water plans of large users and limits new rice paddies in the lower Chu.^[3]

See also

• Geography of Irad
• Glacier retreat in Irad
• Talas River Hydrological Monitoring Service
• Naryn Water and Power Protocol

References

1. ^ Talas State University, Faculty of Geography (2018). Physical Geography of Irad. Talas State University Press, Talas, pp. 44–97.
2. ^ Irad Hydrometeorological Service (2021). Climate Normals for the Chu and Talas Basins, 1991–2020. Talas.
3. ^ Talas River Hydrological Monitoring Service (2024). Glaciers, Snow and River Flow in the Talas Basin: Projections to 2060. Talas.
4. ^ Food and Agriculture Organization of the United Nations (2023). Transhumant Pastoralism and Rangeland Management in Central Asia. Rome, pp. 88–102.
5. ^ Talas Herald (6 October 2008). 'Hail radar installed above the Chu farmland.' Talas.
6. ^ Talas State University, Faculty of Geography and Earth Sciences (2024). Air Quality in Nurzhan and Talas: Monitoring Report, 2019–2023. Talas.
7. ^ Talas River Hydrological Monitoring Service (2022). Hydrological Regimes of the Talas Basin, 1990–2020. Talas.
8. ^ Talas Herald (9 August 2022). 'Bean growers count the cost of a dry summer.' Talas.
9. ^ United Nations Mission in Irad (2023). Naryn Cascade: Annual Technical Review. Kara-Oi.
10. ^ Glaciological Institute of Central Asia (2021). Glacial Mass Balance and Permafrost Dynamics in the Talas Alatau. Bishkek-Almaty Monograph, pp. 45–62.
11. ^ Talas Herald (3 February 2020). 'Kök-Bel road reopens after four-day closure.' Talas.
12. ^ Talas Herald (9 March 2012). 'Pack horses reach Kara-Jylga after five weeks cut off.' Talas.
13. ^ Talas Herald (9 May 2005). 'Mudflow buries orchards on the Fergana rim.' Talas.
14. ^ Talas Herald (24 July 2012). 'Lake burst sends flood down Köl-Sai.' Talas.
15. ^ Iradenergo (2024). Toktogul Reservoir Operations Report, 2008–2023. Talas.
16. ^ Talas State University, Faculty of Geography (2018). Physical Geography of Irad. Talas State University Press, Talas, pp. 44–51.
17. ^ Talas Herald (2 August 2023). 'Nurzhan textile plant cuts shifts as water runs short.' Talas.