Jombang Regency (Indonesian: Kabupaten Jombang; Javanese: ꦏꦧꦸꦥꦠꦺꦤ꧀ꦗꦺꦴꦩ꧀ꦧꦁ) is a regency of East Java, Indonesia, situated to the southwest of Surabaya. The capital of the regency is the town of Jombang. The regency has an area of 1,159.50 km and a population of 1,202,407 at the 2010 census and 1,318,062 at the 2020 census; the official estimate as of mid-2023 was 1,370,510 (comprising 690,361males and 680,149 females). It became a regency in 1910. It was the birthplace of Abdurrahman Wahid, the 4th president of Indonesia.

The regency is divided administratively into twenty-one districts (kecamatan), tabulated below with their areas and population totals from the 2010 census and the 2020 census, together with the official estimates as of mid-2023. The table also includes the locations of the district administrative centres, the number of administrative villages in each district (comprising 302 rural desa and 4 urban kelurahan - the latter all in Jombang (town) District), and its postal codes.

Kode Wilayah	Name of District (kecamatan)	No. on map	Area in km	Pop'n census 2010	Pop'n census 2020	Pop'n estimate mid 2023	Admin centre	No. of villages	Post codes
35.17.18	Bandar Kedung Mulyo	1	32.50	43,193	49,959	52,604	Banjarsari	11	61462
35.17.01	Perak	2	29.05	50,876	55,975	59,098	Perak	13	61461
35.17.02	Gudo	3	34.39	50,471	55,997	58,822	Gudo	18	61463
35.17.08	Diwek	4	47.70	100,969	110,495	114,020	Diwek	20	61471
35.17.03	Ngoro	5	49.86	68,863	77,814	80,348	Ngoro	13	61473
35.17.07	Mojowarno	6	78.62	85,619	95,660	99,451	Mojowarno	19	61475
35.17.04	Bareng	7	94.27	49,470	56,539	59,428	Bareng	13	61474
35.17.05	Wonosalam	8	121.63	30,609	33,520	35,059	Wonosalam	9	61476
35.17.06	Mojoagung	9	60.18	73,004	81,051	83,844	Gambiran	18	61482
35.17.11	Sumobito	10	47.64	77,039	86,385	90,223	Sumobito	21	61483
35.17.19	Jogoroto	11	28.28	62,943	70,760	74,082	Jogoroto	11	61485
35.17.10	Peterongan	12	29.47	63,784	67,822	70,502	Peterongan	14	61481
35.17.09	Jombang (town)	13	36.40	137,233	139,831	143,301	Jombatan	20	61411 - 61419
35.17.20	Megaluh	14	28.41	36,507	39,725	41,502	Megaluh	13	61457
35.17.13	Tembelang	15	32.94	49,371	54,891	57,135	Pesantren	15	61452
35.17.12	Kesamben	16	51.72	59,990	66,861	68,829	Kesamben	14	61484
35.17.17	Kudu	17	77.75	28,239	31,513	32,868	Randuwatang	11	61454
35.17.21	Ngusikan	18	34.96	20,928	22,793	23,768	Ngusikan	11	61450
35.17.14	Ploso	19	25.96	38,792	41,727	43,430	Ploso	13	61453
35.17.16	Kabuh	20	97.35	39,099	41,311	43,376	Karangpaku	16	61455
35.17.15	Plandaan	21	120.40	35,408	37,383	38,820	Bangsri	13	61456
	Totals		1,159.50	1,202,407	1,318,062	1,370,510	Jombang	306

Note: (a) comprising 4 urban kelurahan (Jombatan, Jelakombo, Kaliwungu and Kepanjen) and 16 desa.

The five last-mentioned districts in the table constitute the folded limestone hilly region in the north, separated from the rest of the regency by the Brantas River. The rest of the regency to the south of the river is more low-lying and constitutes good agricultural land, although the south-east corner (Ngoro, Mojowarno, Bareng and Wonosalam Districts) is more mountainous.

Wind Speed and Humidity Data for Jombang

Month	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Year
Maximum wind speed (km/h)	58	69	60	48	45	29	60	63	182	138	29	40	68.42
Average wind speed (km/h)	45	48	45	48	42	11	14	14	14	15	11	11	26.5
Minimum Wind Speed (km/h)	26	29	37	48	40	0	0	0	0	0	0	0	15
Minimum humidity (%)	55	57.89	59.48	62.67	56.58	53.03	49.16	47.77	41.07	39.06	40.47	48.93	50.92

• (in Indonesian) Official site