Burley/Heyburn
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Burley/Heyburn clear sky chart from 2005-11-05 to 2017-09-17.

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
57%
15160
22%
47019
18%
15127
61%
15127
32%
27513

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
44%
716
13%
2506
12%
716
47%
716
18%
1699
January16th to endNight
48%
768
15%
2597
15%
768
51%
768
21%
1701
February1st to 15thNight
46%
699
11%
2263
11%
697
49%
697
20%
1555
February16th to endNight
44%
632
17%
1895
14%
632
50%
632
26%
1215
March1st to 15thNight
50%
720
16%
2082
11%
720
56%
720
28%
1353
March16th to endNight
44%
768
18%
2112
11%
768
49%
768
27%
1394
April1st to 15thNight
48%
689
20%
1807
9%
689
54%
689
30%
1173
April16th to endNight
51%
540
26%
1620
15%
540
57%
540
34%
925
May1st to 15thNight
56%
539
22%
1619
17%
539
61%
539
36%
906
May16th to endNight
61%
541
18%
1664
17%
541
63%
541
35%
952
June1st to 15thNight
63%
360
19%
1440
23%
360
71%
360
34%
702
June16th to endNight
73%
360
29%
1440
36%
360
83%
360
56%
530
July1st to 15thNight
86%
340
24%
1360
34%
340
90%
340
47%
560
July16th to endNight
83%
456
32%
1490
38%
428
86%
428
61%
594
August1st to 15thNight
77%
539
31%
1611
26%
536
79%
536
54%
761
August16th to endNight
77%
603
40%
1749
29%
603
80%
603
56%
825
September1st to 15thNight
77%
720
34%
1923
23%
720
81%
720
62%
927
September16th to endNight
72%
664
37%
1837
30%
664
76%
664
53%
944
October1st to 15thNight
61%
660
31%
1881
23%
660
68%
660
43%
1028
October16th to endNight
62%
704
27%
2214
24%
704
67%
704
37%
1195
November1st to 15thNight
53%
700
23%
2275
21%
700
58%
700
29%
1332
November16th to endNight
52%
729
20%
2349
16%
729
60%
729
28%
1410
December1st to 15thNight
41%
900
9%
2552
5%
900
44%
900
21%
1829
December16th to endNight
40%
813
12%
2733
11%
813
43%
813
15%
2003

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
6%5%2442445%7%51%
47759
Night
7%6%2442445%7%49%
47199
TransparencyDay
33%311%23%18%9%
47438
Night
34%312%22%16%9%
47021
SeeingDay
9%8%24%26%22%8%
5303
Night
10%6%18%35%24%4
15172

By Month

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
10%11%5%7%6%335%5%7%33%
1432
16th to endDay
10%11%5%6%43445%7%35%
1626
February1st to 15thDay
7%12%37%5%35%46%8%36%
1599
16th to endDay
7%11%36%6%25%45%9%37%
1579
March1st to 15thDay
6%10%36%6%346%6%9%36%
1877
16th to endDay
9%8%36%6%36%5%5%9%36%
2112
April1st to 15thDay
7%7%35%6%35%6%7%8%40%
2140
16th to endDay
8%5%245%25%46%7%48%
2340
May1st to 15thDay
6%3143345%6%8%52%
2331
16th to endDay
7%5%25%6%35%6%6%8%43%
2447
June1st to 15thDay
6%424325%5%6%7%52%
2520
16th to endDay
211112335%74%
2520
July1st to 15thDay
211222346%7%66%
2520
16th to endDay
2211223445%68%
2573
August1st to 15thDay
3223235%5%6%64%
2340
16th to endDay
11231225%6%71%
2450
September1st to 15thDay
311213347%68%
2037
16th to endDay
5%312312335%67%
1828
October1st to 15thDay
8%41342445%6%53%
1749
16th to endDay
6%5%145%3445%7%51%
1656
November1st to 15thDay
9%7%15%425%448%45%
1584
16th to endDay
7%9%35%6%345%6%7%40%
1594
December1st to 15thDay
12%9%46%6%35%5%5%6%33%
1406
16th to endDay
12%13%6%7%6%35%45%7%26%
1499
January1st to 15thNight
10%9%46%6%35%46%8%35%
2506
16th to endNight
11%10%36%5%2335%6%40%
2597
February1st to 15thNight
9%9%36%6%35%5%5%7%36%
2252
16th to endNight
6%7%36%5%26%5%6%10%38%
1895
March1st to 15thNight
5%6%35%6%35%6%6%9%41%
2082
16th to endNight
9%8%35%425%46%8%40%
2112
April1st to 15thNight
6%7%246%35%46%7%44%
1807
16th to endNight
7%5%25%33335%7%52%
1620
May1st to 15thNight
44145%345%5%6%53%
1619
16th to endNight
7%6%1343447%8%47%
1664
June1st to 15thNight
5%3142235%6%8%53%
1440
16th to endNight
212212235%75%
1440
July1st to 15thNight
1112225%5%6%8%62%
1440
16th to endNight
111131245%7%69%
1592
August1st to 15thNight
12132245%5%9%63%
1620
16th to endNight
2213322347%67%
1749
September1st to 15thNight
1213212347%69%
1923
16th to endNight
5%212323335%66%
1837
October1st to 15thNight
7%413313336%60%
1881
16th to endNight
6%4134245%6%8%51%
2214
November1st to 15thNight
10%6%24324448%48%
2275
16th to endNight
6%6%246%35%5%6%8%44%
2349
December1st to 15thNight
10%9%48%6%35%5%6%9%31%
2552
16th to endNight
14%12%48%5%2445%7%29%
2733

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
50%6%19%18%31
1432
16th to endDay
49%5%18%19%5%1
1626
February1st to 15thDay
47%6%19%20%5%1
1599
16th to endDay
46%5%16%24%6%1
1579
March1st to 15thDay
45%5%16%24%7%1
1877
16th to endDay
47%415%21%9%
2112
April1st to 15thDay
41%414%24%13%1
2140
16th to endDay
36%212%26%19%2
2340
May1st to 15thDay
29%39%33%21%2
2331
16th to endDay
39%312%28%14%1
2450
June1st to 15thDay
30%411%27%20%5%
2520
16th to endDay
14%1422%38%18%
2520
July1st to 15thDay
16%2318%35%23%
2371
16th to endDay
17%2211%24%41%
2413
August1st to 15thDay
19%2415%27%30%
2325
16th to endDay
13%2320%35%24%
2450
September1st to 15thDay
16%28%18%32%21%
2037
16th to endDay
21%25%28%30%11%
1828
October1st to 15thDay
31%212%31%16%5%
1749
16th to endDay
33%212%29%19%1
1656
November1st to 15thDay
40%412%27%11%2
1584
16th to endDay
43%317%26%8%1
1594
December1st to 15thDay
52%7%18%17%4
1406
16th to endDay
57%419%14%3
1499
January1st to 15thNight
48%6%17%22%41
2506
16th to endNight
45%5%16%24%6%2
2597
February1st to 15thNight
48%5%17%21%7%
2263
16th to endNight
41%5%20%25%7%1
1895
March1st to 15thNight
39%5%17%24%10%2
2082
16th to endNight
41%414%27%10%1
2112
April1st to 15thNight
38%412%28%13%2
1807
16th to endNight
32%310%28%23%1
1620
May1st to 15thNight
30%310%25%26%4
1620
16th to endNight
32%312%29%17%4
1665
June1st to 15thNight
28%211%23%25%7%
1440
16th to endNight
13%1416%35%28%
1440
July1st to 15thNight
19%2314%30%29%
1360
16th to endNight
13%1311%23%46%
1490
August1st to 15thNight
18%2417%23%33%
1611
16th to endNight
17%2215%30%32%
1749
September1st to 15thNight
15%2416%34%26%
1923
16th to endNight
21%2424%31%16%
1837
October1st to 15thNight
27%210%28%23%7%
1881
16th to endNight
28%312%29%20%4
2214
November1st to 15thNight
36%314%23%17%4
2275
16th to endNight
37%416%28%11%
2349
December1st to 15thNight
50%5%21%17%5%
2552
16th to endNight
56%416%18%3
2733

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
15%8%21%21%20%13%
60
16th to endDay
18%6%11%29%29%5%
79
February1st to 15thDay
18%7%23%22%23%4
114
16th to endDay
16%21%29%21%10%
238
March1st to 15thDay
10%18%33%20%14%1
270
16th to endDay
13%19%35%21%8%1
288
April1st to 15thDay
11%15%31%17%15%7%
269
16th to endDay
12%16%30%22%14%3
270
May1st to 15thDay
8%10%29%27%17%6%
288
16th to endDay
10%9%20%22%22%13%
330
June1st to 15thDay
8%10%27%23%19%9%
315
16th to endDay
25%29%30%22%9%
315
July1st to 15thDay
3116%37%30%10%
305
16th to endDay
2222%37%27%7%
327
August1st to 15thDay
5%223%29%30%7%
315
16th to endDay
3318%25%35%14%
332
September1st to 15thDay
5%5%18%27%26%17%
315
16th to endDay
6%6%17%31%25%12%
260
October1st to 15thDay
6%7%20%30%25%8%
189
16th to endDay
13%228%22%29%4
96
November1st to 15thDay
16%111%20%43%7%
90
16th to endDay
22%6%16%37%15%1
90
December1st to 15thDay
25%8%23%34%8%
84
16th to endDay
18%415%34%18%7%
64
January1st to 15thNight
15%9%19%30%21%4
720
16th to endNight
17%8%16%31%23%2
768
February1st to 15thNight
15%6%21%33%20%1
704
16th to endNight
9%8%27%35%15%2
632
March1st to 15thNight
8%9%23%37%18%2
720
16th to endNight
13%9%25%35%14%1
768
April1st to 15thNight
9%11%23%35%17%3
689
16th to endNight
10%9%24%36%16%2
540
May1st to 15thNight
6%7%21%37%24%2
540
16th to endNight
9%5%17%30%31%5%
543
June1st to 15thNight
7%417%41%26%3
360
16th to endNight
3216%41%29%5%
360
July1st to 15thNight
17%45%40%4
340
16th to endNight
18%43%41%4
456
August1st to 15thNight
2112%44%36%2
539
16th to endNight
3111%44%35%5%
603
September1st to 15thNight
2112%35%36%11%
720
16th to endNight
5%214%32%32%12%
664
October1st to 15thNight
10%417%34%28%5%
660
16th to endNight
9%5%16%36%27%5%
704
November1st to 15thNight
14%7%18%28%27%3
700
16th to endNight
10%7%21%35%21%4
729
December1st to 15thNight
16%6%24%34%17%2
900
16th to endNight
20%9%17%35%14%2
813
Page generated at 2017-09-18 06:38:21. Version ac04

Copyright 2017 A. Danko


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