Canadian Extreme Rainfall Summary By Province - Environment Canada Trend Analysis

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Canadian Rain?  "Yup, I thought I felt something"
The following tables summarize the trends and significance of extreme rainfall patterns over durations of 5 minutes to 24 hours based on Environment Canada's latest Engineering Climate Datasets. These short term rainfall intensities govern flooding in urban areas with quick response times (i.e., short 'time of concentration', or 'flashy' catchments and watersheds). Data indicates that most extreme rainfall trends are not statistically significant (trends will randomly increase or decrease over time as new annual maximum rainfall totals are observed). A small percentage of short term rainfall intensities show statistically significant decreases or increases.

5 Minute Extreme Rainfall Trend
Province Station Count

Trend / Significance
AB  
BC  
MB  
NB  
NL  
NS  
NT  
NU  
ON  
PE  
QC  
SK  
YT  
Canada
Decrease/ Significant

2

1
1
1


2
1
7

1
16
Decrease/ Not Significant
17
20
8
3
6
2
2
1
51
1
61
15
2
189
No Data
1
56
2
1
1
2
1
5
15

8
1
1
94
Increase/ Not Significant
12
50
15
8
10
10
4
3
60
1
55
19
4
251
Increase/ Significant

1
2
1
1



5

4

1
15
Canada
30
129
27
14
19
15
7
9
133
3
135
35
9
565
10 Minute Extreme Rainfall Trend
Province Station Count

Trend / Significance
AB  
BC  
MB  
NB  
NL  
NS  
NT  
NU  
ON  
PE  
QC  
SK  
YT  
Canada
Decrease/ Significant

1
1


1


3
1
9


16
Decrease/ Not Significant
15
27
9
6
8
3
2
2
42
1
57
15
2
189
No Data
1
52
1

1
2
1
1
13

11

2
85
Increase/ Not Significant
14
47
14
8
10
9
3
6
69
1
53
19
4
257
Increase/ Significant

2
2



1

6

5
1
1
18
Canada
30
129
27
14
19
15
7
9
133
3
135
35
9
565
15 Minute Extreme Rainfall Trend
Province Station Count

Trend / Significance
AB  
BC  
MB  
NB  
NL  
NS  
NT  
NU  
ON  
PE  
QC  
SK  
YT  
Canada
Decrease/ Significant

2
1

1
1


2

4


11
Decrease/ Not Significant
16
26
8
4
7
3
3
3
49
2
64
19
5
209
No Data
1
51
1
2

2
1

13

8

1
80
Increase/ Not Significant
13
49
14
8
11
9
2
6
63
1
55
15
2
248
Increase/ Significant

1
3



1

6

4
1
1
17
Canada
30
129
27
14
19
15
7
9
133
3
135
35
9
565
30 Minute Extreme Rainfall Trend
Province Station Count

Trend / Significance
AB  
BC  
MB  
NB  
NL  
NS  
NT  
NU  
ON  
PE  
QC  
SK  
YT  
Canada
Decrease/ Significant

4
1
1



1


3


10
Decrease/ Not Significant
16
23
10
4
5
3
4
3
42
2
57
18
3
190
No Data
1
51
2
1

1
1
1
12

6


76
Increase/ Not Significant
13
49
11
8
12
10
1
4
67
1
68
14
5
263
Increase/ Significant

2
3

2
1
1

12

1
3
1
26
Canada
30
129
27
14
19
15
7
9
133
3
135
35
9
565
1 Hour Extreme Rainfall Trend
Province Station Count

Trend / Significance
AB  
BC  
MB  
NB  
NL  
NS  
NT  
NU  
ON  
PE  
QC  
SK  
YT  
Canada
Decrease/ Significant
1
5
1
1

1


1

4
1

15
Decrease/ Not Significant
13
34
13
5
4
2
2
6
48
1
64
16
2
210
No Data

5






2

1


8
Increase/ Not Significant
15
79
11
7
13
12
4
3
77
2
65
15
5
308
Increase/ Significant
1
6
2
1
2

1

5

1
3
2
24
Canada
30
129
27
14
19
15
7
9
133
3
135
35
9
565
2 Hour Extreme Rainfall Trend
Province Station Count

Trend / Significance
AB  
BC  
MB  
NB  
NL  
NS  
NT  
NU  
ON  
PE  
QC  
SK  
YT  
Canada
Decrease/ Significant
1
4
1

 1



3

6
1

17
Decrease/ Not Significant
17
41
15
6
6
7
2
5
53

68
17
2
239
No Data

2




1
1
2


1

7
Increase/ Not Significant
10
74
11
8
10
8
4
3
67
3
60
15
6
279
Increase/ Significant
2
8


2



8

1
1
1
23
Canada
30
129
27
14
19
15
7
9
133
3
135
35
9
565

6 Hour Extreme Rainfall Trend
Province Station Count

Trend / Significance
AB  
BC  
MB  
NB  
NL  
NS  
NT  
NU  
ON  
PE  
QC  
SK  
YT  
Canada
Decrease/ Significant
1
3






3

2
1

10
Decrease/ Not Significant
17
48
10
4
8
5
2
3
56

62
15
3
233
No Data

1



1


2


1

5
Increase/ Not Significant
12
69
17
9
10
8
5
6
65
2
67
17
6
293
Increase/ Significant

8

1
1
1


7
1
4
1

24
Canada
30
129
27
14
19
15
7
9
133
3
135
35
9
565

12 Hour Extreme Rainfall Trend
Province Station Count

Trend / Significance
AB  
BC  
MB  
NB  
NL  
NS  
NT  
NU  
ON  
PE  
QC  
SK  
YT  
Canada
Decrease/ Significant
1
3

1




2

2
2

10
Decrease/ Not Significant
16
51
9
16
10
5
1
3
53
1
68
16
4
241
No Data

2






3


1

7
Increase/ Not Significant
13
60
18
13
7
10
6
5
67
1
61
15
5
276
Increase/ Significant

13


2


1
8
1
4
1

31
Canada
30
129
27
30
19
15
7
9
133
3
135
35
9
565

24 Hour Extreme Rainfall Trend
Province Station Count

Trend / Significance
AB  
BC  
MB  
NB  
NL  
NS  
NT  
NU  
ON  
PE  
QC  
SK  
YT  
Canada
Decrease/ Significant

4

1




3

2
2

12
Decrease/ Not Significant
12
54
10
4
9
3
1
2
60
1
64
18
4
242
No Data

1



2


2


1

6
Increase/ Not Significant
17
63
17
6
8
9
5
6
59
2
65
14
4
275
Increase/ Significant
1
7

3
2
1
1
1
9

4

1
30
Canada
30
129
27
14
19
15
7
9
133
3
135
35
9
565