Training Effect

OH WOW! 

That sucks sorry. 

Yes, but it's not only a problem for me. All my friends that have Garmin watches, for example FR225 or FR735, have the same wrong temperature in the Garmin Connect map, because they run near my town. The wrong temperature depends not on the type of watch, but probably on the weather station that gives the temperature value to Garmin: Garmin should definitely fix it as soon as possible. If someone of Garmin wants more detail, I can explain where I live and which is the town affected. It's not a small town, it's about 30.000 people and there are a lot of tourists that run and ride here, so this problem affects a lot of people.

Question, in you phone using a weather app does it show correct temperature? 

Garmin Connect will read the data from the phone. It does not 'choose' the weather station, that's what your phone does.

Perhaps you need to be addressing the source of the weather data on your phone. It's quite possible that the nearest weather source is some distance away. 

I did a test today to get into this matter as I was also experiencing zero anaerobic benefit from a workout of 3 x 8 Minutes at 90 % VO2max, which in the past would have gotten me some anaerobic TE. So today I did 10 x 400 meters at around 120% VO2max and got a good anaerobic benefit (3.3). Interestingly, my heart rate never even got into zone 5 due to the duration of the intervals (~78 seconds). It seems to me they have, rightfully so, decoupled training effect for the anaerobic portion from time in heart rate zones and are considering rise in heart rate and or speed/effort. In the past maximising zone 5 heart rate would have given the highest anaerobic TE in my experience, which was just wrong, as those are VO2max workouts that hardly improve your anaerobic capabilities.

In summary, for me, the system works much better than in the past and gives proper anaerobic TE, which unfortunately means way less anaerobic TE for VO2max workouts.

And how do I know which weather app my phone is using? Usually I use the app www.ilmeteo.it and it's correct, but I don't know which app my phone is using. I have Android.

The strange thing is that right now my watch reports:

7°C 27/15 N32km/h  sun with some clouds

all the informations are correct, except the first number i.e. actual temperature. Other informations are correct: the max of the day 27°C and the min 15°C. If I click it reports correct hourly and daily temperature:

1 pm sun 26° 0%rain

2 pm sun 27°C 0%rain

3 pm sun with clouds 26°C probability of rain 20%

4 pm cluds with rain 24°C proability of rain 20%

Daily

WED sun and clouds 27/15

Thurs sun and clouds 25/15

Friday sun and clouds 27/16

Saturday  sun and clouds 27/17

Today first workout with anaerobic training effect.

I did 5x1km + 4 x400 , and all intervals were faster that usual with a rest period a bit longer than usual between intervals and it was really hard for me. At the end I had :

Training effect : anaerobic

Aerobic 3,4 impacting VO2max

Anaerobic 3 Impacting Economy and Anaerobic Fitness

Load 202

It was really hard and probably at the end I couldn't do other intervals, but at least the result was in line with what I was looking for.

It seems that one has to push really hard to get an anaerobic training effect

Which is why I asked about max HR (not to be confused with VO2 Max) and lactate threshold LT settings and mentioned you have to be in bursts effort at or above LT to get high anaerobic TE. 

My money is that if you simply warmup 2-3 km in Z3/Z4 and then do 400m or 800m intervals with 1-2 min recovery in between, you’ll get plenty of anaerobic TE. 

But in general, yes. It’s hard to get high anaerobic TE. There’s a reason hardcore HIIT classes come with a bucket for people to barf into.

on my Expedition i wasn't getting Anaerobic load even after doing 10 to 12 30s or 1 minute max effort intervals. Turned out that my maxhr was set 4-5 beats too high in my profile. I don't remember ever changing this or getting notified of a new max, so something odd happened. Setting it back to my actual observed max put things right.