Kamloops
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Kamloops clear sky chart from 2005-11-05 to 2017-08-12.

This page is a summary of past forecasts. Even though it's based only on forecasts, some people use these pages as clue to a site's climate. But climate data based on actual observation should be preferred (if you can find it!).

Cloud, Transparency and Seeing forecasts are summarized individually. But because good observing conditions require a combination of minimum cloud cover, transparency and seeing, the individual forecast summaries can be difficult to interpret. The observing conditions section counts the combinations of conditions needed for common types of astronomical observation.

Observing Conditions

The following tables count the occurrence of the combinations of forecast and darkness conditions needed for different observations. Conditions are rated by by what percentage of the hours the observation would likely be attempted are usable.
Observation TypeMinimum conditions for hour to be usableOut of hours
Clear of CloudsTransparencySeeingSky Brightness
Planetary:50%(no limit)Average(no limit)Nighttime Hours
Deep Sky:70%Average(no limit)5.9Nighttime Hours
CCD Imaging:70%Below AveragePoor(no limit)Nighttime Hours

Percentages are of nighttime hours per month, or per year, when a particular observing conditions was met. Deep Sky percentages never exceed 50% because the moon is up half the time. Deep sky percentages are much lower for charts at high latitudes because of fewer dark hours in the summer.

Overall

PlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
Night
40%
14652
9%
46337
6%
14626
43%
14626
16%
33993

By Month

MonthDays of MonthPlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
January1st to 15thNight
23%
748
3%
2686
2%
746
26%
746
5%
2310
January16th to endNight
28%
769
5%
2696
4%
769
30%
769
7%
2250
February1st to 15thNight
32%
698
7%
2377
6%
698
34%
698
10%
1906
February16th to endNight
43%
632
10%
1993
9%
632
46%
632
18%
1420
March1st to 15thNight
31%
720
7%
2145
4%
720
35%
720
13%
1636
March16th to endNight
35%
768
9%
2013
3%
768
39%
768
17%
1544
April1st to 15thNight
42%
719
8%
1799
4%
719
43%
719
19%
1358
April16th to endNight
41%
472
12%
1552
9%
472
45%
472
17%
1105
May1st to 15thNight
46%
359
10%
1440
15%
359
50%
359
16%
960
May16th to endNight
52%
374
5%
1475
5%
374
54%
374
14%
1046
June1st to 15thNight
45%
360
1%
1091
0%
360
45%
360
20%
773
June16th to endNight
43%
360
2%
1080
0%
360
43%
360
21%
735
July1st to 15thNight
62%
340
4%
1145
0%
340
63%
340
33%
630
July16th to endNight
66%
376
11%
1372
14%
354
69%
354
33%
684
August1st to 15thNight
76%
352
16%
1400
27%
350
78%
350
37%
666
August16th to endNight
59%
560
17%
1610
14%
560
61%
560
30%
1009
September1st to 15thNight
65%
660
19%
1650
11%
660
66%
660
37%
1029
September16th to endNight
55%
656
18%
1788
12%
656
57%
656
28%
1173
October1st to 15thNight
50%
660
13%
1980
12%
660
52%
660
23%
1334
October16th to endNight
37%
704
10%
2257
6%
704
42%
704
16%
1611
November1st to 15thNight
29%
700
9%
2425
6%
700
34%
700
10%
1893
November16th to endNight
27%
783
5%
2583
2%
783
30%
783
8%
2163
December1st to 15thNight
31%
903
6%
2721
4%
903
34%
903
11%
2212
December16th to endNight
22%
979
6%
3059
2%
979
25%
979
9%
2546

Individual Forecasts

The length of each colored bar in the "occurrence of each Forecast" column is proportional to the number of times the chart forecast that color. The percentages are of the total number of hours per month, or per year, with a particular forecast. The colors as the same as those used in clear sky charts.

Note: Transparency probabilities are only counted for those hours that have 30% or less cloud cover. Seeing probabilities are only counted for those hours that have 80% or less cloud cover. If that's too tricky, try Observing Conditions instead.

Overall

Occurrence of each ForecastData
Points
Cloud CoverDay
7%8%47%7%46%6%6%8%32%
47659
Night
7%9%47%7%46%6%6%7%31%
46493
Cloud CoverDay
8%8%47%7%46%5%6%8%32%
47659
Night
8%9%47%7%46%5%6%7%31%
46496
TransparencyDay
48%11%15%16%6%
47319
Night
50%10%15%15%6%
46337
SeeingDay
13%16%29%24%12%2
6157
Night
13%10%27%29%16%2
14662

By Month

Percentage Cloud Cover NW (2006-)
Color Meanings:
Overcast 90% covered 80% covered 70% covered 60% covered 50% covered 40% covered 30% covered 20% covered 10% covered Clear
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
6%12%6%10%10%7%9%9%7%6%13%
1253
16th to endDay
7%13%6%11%10%5%6%5%6%6%19%
1527
February1st to 15thDay
8%12%5%10%8%5%8%5%5%7%22%
1486
16th to endDay
49%5%8%7%6%7%7%6%8%26%
1481
March1st to 15thDay
5%10%5%9%8%5%6%8%6%9%23%
1815
16th to endDay
5%8%5%9%9%5%7%6%7%8%25%
2211
April1st to 15thDay
6%11%6%8%8%5%7%7%6%9%23%
2149
16th to endDay
7%8%49%8%5%7%6%7%8%25%
2403
May1st to 15thDay
8%9%37%7%37%5%6%7%33%
2511
16th to endDay
12%8%38%6%46%5%7%8%27%
2633
June1st to 15thDay
14%7%36%6%46%6%6%8%28%
2867
16th to endDay
10%6%37%7%46%5%6%7%32%
2880
July1st to 15thDay
5%314435%5%7%7%50%
2742
16th to endDay
5%314425%5%6%7%54%
2702
August1st to 15thDay
43144245%6%8%52%
2467
16th to endDay
6%415%5%35%5%5%8%48%
2238
September1st to 15thDay
6%425%7%33347%51%
1980
16th to endDay
10%7%25%6%45%5%7%7%35%
1841
October1st to 15thDay
7%5%27%8%5%5%5%6%8%35%
1650
16th to endDay
10%10%38%8%5%5%5%6%8%27%
1614
November1st to 15thDay
10%11%5%7%8%45%6%5%7%27%
1433
16th to endDay
7%12%6%10%9%6%7%6%5%6%21%
1364
December1st to 15thDay
7%11%7%11%9%46%6%6%422%
1236
16th to endDay
6%10%5%13%10%5%7%6%7%7%18%
1176
January1st to 15thNight
11%14%7%10%9%6%7%6%5%6%12%
2686
16th to endNight
7%12%7%12%10%5%8%6%5%6%16%
2696
February1st to 15thNight
10%15%5%9%8%46%46%7%21%
2365
16th to endNight
48%49%7%47%7%6%7%33%
1993
March1st to 15thNight
49%46%7%5%7%7%7%7%31%
2145
16th to endNight
48%37%8%5%7%7%7%9%31%
2009
April1st to 15thNight
5%8%47%6%46%7%6%8%33%
1799
16th to endNight
6%7%37%7%46%6%6%8%34%
1552
May1st to 15thNight
8%6%46%7%37%47%7%36%
1439
16th to endNight
11%5%36%7%36%6%6%9%31%
1475
June1st to 15thNight
13%5%37%5%46%6%6%10%30%
1091
16th to endNight
7%327%7%47%47%6%39%
1080
July1st to 15thNight
4313425%5%6%8%53%
1215
16th to endNight
5%2133245%5%9%56%
1467
August1st to 15thNight
221342345%9%59%
1408
16th to endNight
5%425%436%6%7%6%47%
1610
September1st to 15thNight
43145%3446%6%54%
1650
16th to endNight
7%5%245%3445%8%47%
1788
October1st to 15thNight
7%6%35%5%35%6%5%7%42%
1980
16th to endNight
10%8%37%6%5%5%5%5%8%34%
2257
November1st to 15thNight
12%11%48%7%5%6%5%45%28%
2425
16th to endNight
10%13%8%9%9%5%7%6%5%6%18%
2583
December1st to 15thNight
8%12%7%9%9%47%6%5%7%20%
2721
16th to endNight
7%15%6%10%9%5%7%6%5%6%18%
3059

Percentage Cloud Cover SW (2006-)
Color Meanings:
Overcast 90% covered 80% covered 70% covered 60% covered 50% covered 40% covered 30% covered 20% covered 10% covered Clear
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
7%13%7%10%11%6%9%8%6%6%13%
1253
16th to endDay
8%13%6%13%10%5%6%5%6%6%18%
1527
February1st to 15thDay
9%13%5%10%8%5%7%5%5%6%21%
1486
16th to endDay
5%9%5%10%8%6%6%6%7%8%25%
1481
March1st to 15thDay
6%11%6%9%7%5%5%7%8%8%22%
1815
16th to endDay
6%9%49%9%5%7%6%7%8%24%
2211
April1st to 15thDay
7%10%5%9%8%47%5%6%8%23%
2149
16th to endDay
7%8%49%8%47%6%6%9%25%
2403
May1st to 15thDay
8%8%37%6%5%6%5%6%7%33%
2511
16th to endDay
12%8%47%7%36%6%7%8%27%
2633
June1st to 15thDay
15%6%36%7%46%6%6%8%27%
2867
16th to endDay
10%6%27%8%46%5%6%7%32%
2880
July1st to 15thDay
5%3245%25%5%6%8%50%
2742
16th to endDay
5%2135%345%5%7%53%
2702
August1st to 15thDay
4315%42446%9%52%
2467
16th to endDay
6%4245%35%46%8%48%
2238
September1st to 15thDay
6%5%26%6%2445%7%49%
1980
16th to endDay
11%6%36%6%35%5%6%7%35%
1841
October1st to 15thDay
7%7%29%6%5%5%5%5%7%35%
1650
16th to endDay
11%11%49%7%45%5%5%7%27%
1614
November1st to 15thDay
12%11%5%7%8%45%5%5%7%25%
1433
16th to endDay
9%11%7%10%10%6%7%5%5%6%20%
1364
December1st to 15thDay
8%13%8%11%10%46%5%5%5%21%
1236
16th to endDay
7%11%6%11%10%5%7%6%6%8%17%
1176
January1st to 15thNight
13%15%6%10%9%5%7%5%5%5%12%
2685
16th to endNight
8%14%6%12%11%47%6%6%6%15%
2696
February1st to 15thNight
11%16%5%9%7%45%5%5%6%20%
2365
16th to endNight
5%8%310%7%46%6%6%8%32%
1993
March1st to 15thNight
6%10%46%7%48%7%6%8%29%
2145
16th to endNight
5%9%37%8%47%6%6%9%31%
2013
April1st to 15thNight
5%9%48%6%36%7%6%8%32%
1799
16th to endNight
6%8%46%7%46%6%6%8%34%
1552
May1st to 15thNight
7%7%46%7%46%47%7%36%
1439
16th to endNight
11%6%37%6%46%6%6%9%31%
1475
June1st to 15thNight
13%437%5%37%6%6%10%30%
1091
16th to endNight
7%5%35%8%5%6%5%6%7%38%
1080
July1st to 15thNight
4314425%6%6%9%52%
1215
16th to endNight
5%2234235%6%8%56%
1467
August1st to 15thNight
32134245%5%9%58%
1408
16th to endNight
5%415%5%45%6%6%7%47%
1610
September1st to 15thNight
4425%5%3446%6%53%
1650
16th to endNight
7%6%25%44445%7%46%
1788
October1st to 15thNight
7%6%35%5%35%5%5%8%41%
1980
16th to endNight
11%8%36%6%45%46%8%33%
2257
November1st to 15thNight
12%13%47%7%46%45%6%27%
2425
16th to endNight
10%14%8%9%9%47%6%5%6%17%
2583
December1st to 15thNight
9%12%7%9%9%5%7%6%5%6%20%
2721
16th to endNight
9%16%6%10%9%5%7%6%6%6%17%
3059

Transparency (when cloud cover <= 30%)
Color Meanings:
Too cloudy to forecast Poor Below Average Average Above average Transparent
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
67%13%11%5%1
1253
16th to endDay
62%11%15%8%1
1527
February1st to 15thDay
61%11%13%9%2
1486
16th to endDay
53%10%18%12%5%
1481
March1st to 15thDay
57%13%17%10%1
1815
16th to endDay
55%12%17%12%1
2211
April1st to 15thDay
56%13%13%13%3
2149
16th to endDay
53%13%16%12%3
2403
May1st to 15thDay
49%10%16%15%8%
2511
16th to endDay
53%12%16%14%3
2637
June1st to 15thDay
52%11%14%13%5%1
2867
16th to endDay
48%10%15%15%8%
2880
July1st to 15thDay
31%10%16%21%16%3
2583
16th to endDay
27%9%16%28%14%2
2534
August1st to 15thDay
28%10%18%26%13%2
2450
16th to endDay
33%9%18%25%12%1
2238
September1st to 15thDay
34%8%13%28%13%1
1980
16th to endDay
45%10%14%19%7%1
1841
October1st to 15thDay
45%12%18%19%5%
1650
16th to endDay
54%11%17%13%2
1614
November1st to 15thDay
56%12%13%12%4
1433
16th to endDay
61%11%11%12%2
1364
December1st to 15thDay
61%12%11%12%2
1236
16th to endDay
63%11%14%9%2
1176
January1st to 15thNight
70%10%10%7%1
2686
16th to endNight
66%10%12%8%2
2696
February1st to 15thNight
61%9%12%11%4
2377
16th to endNight
48%8%19%16%6%
1993
March1st to 15thNight
49%14%17%14%4
2145
16th to endNight
48%13%19%15%3
2013
April1st to 15thNight
47%11%19%15%4
1799
16th to endNight
46%12%16%19%5%
1552
May1st to 15thNight
45%9%14%17%11%1
1440
16th to endNight
48%11%18%14%6%
1475
June1st to 15thNight
47%9%17%18%5%1
1091
16th to endNight
43%9%17%19%9%
1080
July1st to 15thNight
28%7%17%22%19%4
1145
16th to endNight
24%8%17%27%18%3
1372
August1st to 15thNight
21%8%20%26%19%3
1400
16th to endNight
33%10%17%22%14%1
1610
September1st to 15thNight
29%8%15%28%16%2
1650
16th to endNight
36%9%17%21%11%3
1788
October1st to 15thNight
40%10%16%23%8%
1980
16th to endNight
48%10%20%18%2
2257
November1st to 15thNight
57%10%12%12%5%
2425
16th to endNight
64%11%11%8%3
2583
December1st to 15thNight
61%10%15%11%2
2721
16th to endNight
63%11%12%9%2
3059

Seeing (when cloud cover <= 80%)
Color Meanings:
Too cloudy to forecast Bad 1/5 Poor 2/5 Average 3/5 Good 4/5 Excellent 5/5
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
5%6%16%31%25%15%
60
16th to endDay
12%20%31%23%10%1
64
February1st to 15thDay
13%22%30%23%8%
146
16th to endDay
8%21%29%27%11%1
221
March1st to 15thDay
27%27%29%14%1
270
16th to endDay
17%28%36%12%3
288
April1st to 15thDay
18%21%31%20%7%
269
16th to endDay
12%27%36%15%5%1
270
May1st to 15thDay
15%21%30%20%8%2
288
16th to endDay
13%12%29%22%19%2
348
June1st to 15thDay
17%13%28%24%14%1
662
16th to endDay
14%11%30%26%14%2
675
July1st to 15thDay
9%12%27%31%17%1
517
16th to endDay
8%11%27%35%12%4
371
August1st to 15thDay
6%6%23%36%21%6%
300
16th to endDay
7%18%31%28%11%2
268
September1st to 15thDay
11%16%29%23%16%2
255
16th to endDay
13%18%31%24%9%2
255
October1st to 15thDay
17%21%27%20%11%1
255
16th to endDay
17%13%26%23%19%
126
November1st to 15thDay
21%27%30%15%4
65
16th to endDay
13%20%31%13%10%11%
60
December1st to 15thDay
13%23%20%16%18%8%
60
16th to endDay
9%10%37%23%15%3
64
January1st to 15thNight
20%10%31%23%12%1
750
16th to endNight
14%8%31%30%12%2
769
February1st to 15thNight
19%8%27%31%10%2
704
16th to endNight
8%10%28%30%19%1
632
March1st to 15thNight
12%16%33%26%9%1
720
16th to endNight
12%14%29%27%12%2
768
April1st to 15thNight
10%13%26%29%17%3
719
16th to endNight
9%12%30%33%12%1
472
May1st to 15thNight
10%8%27%31%18%2
360
16th to endNight
14%5%20%33%24%2
375
June1st to 15thNight
13%6%26%34%16%1
360
16th to endNight
10%6%31%32%16%2
360
July1st to 15thNight
6%420%40%26%
340
16th to endNight
6%318%43%26%1
376
August1st to 15thNight
3113%33%39%7%
352
16th to endNight
9%421%35%26%2
560
September1st to 15thNight
6%7%17%28%32%8%
660
16th to endNight
12%8%20%31%23%3
656
October1st to 15thNight
11%8%24%32%19%2
660
16th to endNight
19%11%27%25%14%2
704
November1st to 15thNight
19%16%29%27%6%1
700
16th to endNight
19%14%27%25%10%2
783
December1st to 15thNight
15%11%29%31%12%
903
16th to endNight
17%12%34%25%8%
979
Page generated at 2017-08-13 11:16:53. Version ac04

Copyright 2017 A. Danko


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