Precipitation return levels in Finland

The precipitation return levels presented in the tables can be used for risk assessment of abundant precipitation and the use of design rainfall. The values have been calculated for those weather stations of the Finnish Meteorological Institute from which long (typically over 50 years) and reliable time series can be obtained. When applied to other locations, one should select the weather station which is climatically closest, which, in practice, usually is the nearest station. The calculated values are based on observations which means that the predicted impacts of climate change are not included.

Save the data as an Excel-file

Choose time period:

6 hours
24 hours
5 days
14 days
1 month

Return levels for precipitation of six hours at weather stations in different parts of Finland. With the help of the table it is possible to examine precipitation (in millimetres) which has a frequency (return period) of either 10, 20, 50, 100 or 500 years. The table shows the best estimate (average - avg.) and the limits within which 95% of cases occur. Empty cell means that the method used was not applicable for estimating the return levels in question.

ret.period	1201 Jokioinen observatory			7501 Sodankylä
years	95%	avg.	95%	95%	avg.	95%
10	31	44	56	21	26	33
20	38	54	69	23	29	37
50	50	71	92	25	33	42
100	60	86	112	26	36	47
500	-	-	-	30	43	57

Return levels for precipitation of 24 hours at weather stations in different parts of Finland. With the help of the table it is possible to examine precipitation (in millimetres) which has a frequency (return period) of either 10, 20, 50, 100 or 500 years. The table shows the best estimate (average - avg.) and the limits within which 95% of cases occur. Empty cell means that the method used was not applicable for estimating the return levels in question.

ret.period	304 Helsinki Kaisaniemi			1101 Turku airport			1201 Jokioinen observatory			1501 Utti airport
years	95%	avg.	95%	95%	avg.	95%	95%	avg.	95%	95%	avg.	95%
10	47	55	66	47	55	64	48	57	67	42	48	56
20	52	64	76	53	64	75	54	67	80	46	54	63
50	60	76	92	62	76	91	65	82	98	51	63	74
100	68	86	105	71	87	104	75	95	115	56	70	83
500	89	115	141	94	118	142	104	133	162	70	88	105

ret.period	2401 Jyväskylä airport			3201 Kauhava airport			3801 Joensuu airport			5401 Oulu airport
years	95%	avg.	95%	95%	avg.	95%	95%	avg.	95%	95%	avg.	95%
10	46	54	64	44	51	61	45	52	61	38	45	54
20	52	63	75	49	60	72	50	60	72	42	53	63
50	61	76	92	56	71	88	59	73	88	50	64	77
100	69	88	106	66	84	101	67	84	101	57	73	89
500	-	-	-	88	114	139	90	115	140	-	-	-

ret.period	6801 Kuusamo airport			7501 Sodankylä			8201 Muonio kk			9601 Ivalo
years	95%	avg.	95%	95%	avg.	95%	95%	avg.	95%	95%	avg.	95%
10	37	43	51	35	39	45	43	51	61	43	53	64
20	41	50	60	38	43	50	49	60	72	50	64	78
50	48	60	73	42	49	57	57	72	87	63	82	100
100	54	69	-	44	54	63	65	83	100	75	98	121
500	-	-	-	53	65	76	86	111	136	-	-	-

Return levels for precipitation of five days at weather stations in different parts of Finland. With the help of the table it is possible to examine precipitation (in millimetres) which has a frequency (return period) of either 10, 20, 50, 100 or 500 years. The table shows the best estimate (average - avg.) and the limits within which 95% of cases occur. Empty cell means that the method used was not applicable for estimating the return levels in question.

ret.period	304 Helsinki Kaisaniemi			1101 Turku airport			1201 Jokioinen observatory			1501 Utti airport
years	95%	avg.	95%	95%	avg.	95%	95%	avg.	95%	95%	avg.	95%
10	75	85	100	72	80	91	70	79	65	74	76	83
20	85	97	126	80	90	111	78	90	124	79	82	92
50	96	112	160	89	102	142	89	106	154	84	87	105
100	103	122	179	95	110	157	96	119	-	87	90	116
500	116	144	219	105	125	186	110	-	-	91	95	127

ret.period	2401 Jyväskylä airport			3201 Kauhava airport			3801 Joensuu airport			5401 Oulu airport
years	95%	avg.	95%	95%	avg.	95%	95%	avg.	95%	95%	avg.	95%
10	72	76	83	-	-	-	72	82	96	53	58	66
20	77	82	94	-	-	-	82	94	119	58	64	78
50	83	90	113	-	-	-	93	107	156	64	71	98
100	87	94	124	-	-	-	100	116	172	67	75	106
500	93	101	137	-	-	-	111	133	-	71	82	121

ret.period	6801 Kuusamo airport			7501 Sodankylä			8201 Muonio kk			9601 Ivalo
years	95%	avg.	95%	95%	avg.	95%	95%	avg.	95%	95%	avg.	95%
10	-	-	-	57	63	72	60	67	78	62	72	89
20	-	-	-	63	71	89	66	75	97	71	83	117
50	-	-	-	71	82	111	74	86	120	82	97	148
100	-	-	-	77	91	126	80	94	134	88	107	166
500	-	-	-	87	109	-	90	112	165	98	128	205

Return levels for precipitation of fourteen days at weather stations in different parts of Finland. With the help of the table it is possible to examine precipitation (in millimetres) which has a frequency (return period) of either 10, 20, 50, 100 or 500 years. The table shows the best estimate (average - avg.) and the limits within which 95% of cases occur. Empty cell means that the method used was not applicable for estimating the return levels in question.

ret.period	304 Helsinki Kaisaniemi			1101 Turku airport			1201 Jokioinen observatory			1501 Utti airport
years	95%	avg.	95%	95%	avg.	95%	95%	avg.	95%	95%	avg.	95%
10	119	126	137	116	127	143	115	119	129	111	116	126
20	126	135	161	127	141	171	123	128	141	118	124	140
50	134	144	-	140	156	-	130	135	157	125	131	161
100	138	149	-	148	166	-	134	139	169	128	135	179
500	144	156	-	159	184	-	139	145	190	133	142	190

ret.period	2401 Jyväskylä airport			3201 Kauhava airport			3801 Joensuu airport			5401 Oulu airport
years	95%	avg.	95%	95%	avg.	95%	95%	avg.	95%	95%	avg.	95%
10	104	112	123	-	-	-	-	122	134	83	88	96
20	112	122	142	-	-	-	-	130	144	88	94	106
50	121	133	169	-	-	-	-	137	161	94	101	121
100	127	141	183	-	-	-	-	140	174	97	105	133
500	138	157	210	-	-	-	-	144	198	102	112	145

ret.period	6801 Kuusamo airport			7501 Sodankylä			8201 Muonio kk			9601 Ivalo
years	95%	avg.	95%	95%	avg.	95%	95%	avg.	95%	95%	avg.	95%
10	98	101	109	89	94	101	91	101	118	87	99	120
20	104	107	121	94	100	112	100	113	-	98	113	-
50	108	113	141	99	107	131	112	130	-	111	131	-
100	111	115	151	101	110	141	119	142	-	119	144	-
500	114	119	158	106	116	151	132	-	-	133	-	-

Return levels for precipitation of a month at weather stations in different parts of Finland. With the help of the table it is possible to examine precipitation (in millimetres) which has a frequency (return period) of either 10, 20, 50, 100 or 500 years. The table shows the best estimate (average - avg.) and the limits within which 95% of cases occur. Empty cell means that the method used was not applicable for estimating the return levels in question.

ret.period	304 Helsinki Kaisaniemi			1101 Turku airport			1201 Jokioinen observatory			1501 Utti airport
years	95%	avg.	95%	95%	avg.	95%	95%	avg.	95%	95%	avg.	95%
10	144	149	157	138	148	158	-	141	148	144	153	165
20	155	162	171	147	161	173	-	149	157	153	164	182
50	166	175	190	157	175	195	-	157	169	162	174	204
100	172	182	204	164	183	213	-	161	177	167	180	221
500	183	194	233	175	198	242	-	166	195	174	188	245

ret.period	2401 Jyväskylä airport			3201 Kauhava airport			3801 Joensuu airport			5401 Oulu airport
years	95%	avg.	95%	95%	avg.	95%	95%	avg.	95%	95%	avg.	95%
10	145	151	163	-	-	-	149	157	171	110	124	146
20	155	162	178	-	-	-	162	171	191	124	142	179
50	164	172	198	-	-	-	175	186	216	141	164	221
100	172	178	212	-	-	-	183	195	235	153	180	246
500	180	186	239	-	-	-	195	208	267	-	-	-

ret.period	6801 Kuusamo airport			7501 Sodankylä			8201 Muonio kk			9601 Ivalo
years	95%	avg.	95%	95%	avg.	95%	95%	avg.	95%	95%	avg.	95%
10	-	131	138	119	124	132	-	131	138	114	121	132
20	-	139	148	127	133	144	-	139	147	123	131	146
50	-	148	162	136	144	160	-	146	157	131	141	166
100	-	153	173	141	150	173	-	149	163	135	146	182
500	-	160	193	150	160	195	-	153	173	143	155	202

Reference:

Venäläinen, A., Saku, S., Kilpeläinen, T., Jylhä, K., Tuomenvirta, H., Vajda, A., Räisänen, J. & Ruosteenoja, K. 2007. Sään ääri-ilmiöistä Suomessa. (Aspects about climate extremes in Finland. Abstract in English.) Ilmatieteen laitos, Helsinki. Ilmatieteen laitoksen raportteja 2007:4. 81 s. http://hdl.handle.net/10138/1138

More information in Climateguide.fi:

Design rainfall information is used as a risk assessment tool in water management

Flood risk management measures can be used to prepare for floods

Precipitation will increase and heavy rain events will intensify

Intensity and frequency of short-duration rainfall in Finland (visualization)